Image Credits

• 3G cellular network: "USB modem for PC, 2008. Adaptible for 3G mobile data (UMTS, HSxPA). Telenor version, Norway.", by HLundgaard, 2008, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• 5G cellular network: "*SAMSUNG Galaxy Note10 SAMSUNG Galaxy Note10 5G SAMSUNG Galaxy Note10+ SAMSUNG Galaxy Note10+ 5G", by NOTE PHONE, 2019, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Abacus: "Reconstruction of a Roman Abacus, made by the RGZ Museum in Mainz, 1977The original is bronze and is held by the Bibliothèque nationale de France, in Paris.", by Photographer: Mike Cowlishaw (aus der englischen Wikipedia), 2004, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Abjad: "Specimen of the only certainly deciphered word in the Proto-Sinaitic script, b‘lt.", by unknown Uploaded by Kwamikagami at en.wikipedia, 1500, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Absorption refrigerator: "Device of Ferdinand Carré for making ice. Illustration from book "Water" by Gaston Tissandier 2th Edition (1869)", by Auguste Jahandier, 1869, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Accordion: "A World of Accordions", by Henry Doktorski, 2005, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Acetylsalicylic acid: "Ball-and-stick model of the aspirin molecule, as found in the solid state. Single-crystal X-ray diffraction data from Kim, Y.; Machida, K.; Taga, T.; Osaki, K. (1985). "Structure Redetermination and Packing Analysis of Aspirin Crystal". Chem. Pharm. Bull. 33 (7): 2641-2647. ISSN 1347-5223.[dead link]", by Ben Mills, 2008, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Acheson process: "Carborondum furnace with walls removed after heating", by Unknown authorUnknown author, 1908, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Acheulean stone tool: "Cordate shaped hand axe (replica)", by José-Manuel Benito Álvarez (España) —> Locutus Borg, 2007, licensed under CC BY-SA 2.5, via Wikimedia Commons. View source. View in tree.
• Achromatic lens: "Chromatic aberration diagram", by Bob Mellish, 2006, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Acrylic glass: "Pieces of perspex from German plane which had been shot down,and subsequently acquired by 423170 Pte Ralph Turner, 21st Infantry Battalion, 2NZEF, for making souvenirs. These formed part of his trench kit, (see 2007.10.1).", by Unknown authorUnknown author, 2007, licensed under CC BY 4.0, via Wikimedia Commons. View source. View in tree.
• Active-pixel sensor: "Ov6920-01.jpg", licensed under CC BY 2.5, via Wikimedia Commons. View source. View in tree.
• Advanced driver-assistance system: "Driving in traffic with Tesla's autopilot controlling distance from the lead car and centering the vehicle in the lane. Vehicle is a 2017 Model X 75D with dark interior.", by Ian Maddox, 2017, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Advanced Encryption Standard: "Each regular round involves four steps. First is the Byte Sub step, where each byte of the block is replaced by its substitute in an S-box. Next is the Shift Row step, followed by the Mix Column step. Matrix multiplication is performed. The final step is Add Round Key. This simply XORs in the subkey for the current round.", by John Savard, 1999, licensed under CC0, via Wikimedia Commons. View source. View in tree.
• Aeolipile: "From the book, "The Science-History of the Universe" by Francis Rolt-Wheeler, Copyright 1910, The Current Literature Publishing Company, New York. The illustration is from page 309. This may be the beginnings of the steam engine. Flickr data on 2011-08-16: Tags: vintage, book, image, illustration, drawing, public domain, copyright free, pre-1923 License: CC BY 2.0 User: perpetualplum Sue Clark", by Sue Clark, 2009, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Aerogel: "Aerogel: Though with a ghostly appearance like an hologram, aerogel is very solid. It feels like hard styrofoam to the touch.", by Courtesy NASA/JPL-Caltech, 1994, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Aerosledge: "RF-8.jpg", licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Agar: "2 cubes of green tea yokan", by Sjschen, 2007, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Agar plate: "K12 E Coli colonies on a plate.", by Madprime, 2007, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Air conditioner: "MITSUBISHI ELECTRIC WINDOW TYPE AIR CONDITIONER OUTDOOR UNIT", by Dinkun Chen, 2023, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Air fryer: "A generic air fryer", by Ashley Pomeroy, 2024, licensed under CC BY 4.0, via Wikimedia Commons. View source. View in tree.
• Air gun: "A Girandoni System Austrian Repeating Air Rifle, Circa 1795, believed to have been taken on the Lewis & Clark Army Corps of Discovery Expedition 1803-1806.", by Army Heritage Museum, U.S. Army, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Air-independent submarine: "Ictineo II.jpg", licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Aircraft carrier: "HMS Furious (British Aircraft Carrier, 1917-1948) At sea, circa 1935-36, with a flight of Blackburn "Baffin" torpedo planes overhead. U.S. Naval Historical Center Photograph.", 1935, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Aircraft carrier with full-length flight deck: "HMS Argus (I49) in harbour in 1918, painted in dazzle camouflage, with a Renown class battlecruiser in the distance", by Unknown Navy personnel, 1918, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Aircraft dope: "Royal Aircraft Factory B.E.2c Serial Number 2699 at the Imperial War Museum London September 2005", by Photograph taken by MilborneOne, 2005, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Aircraft steam catapult: "Bow view of the U.S. Navy aircraft carrier USS Saratoga (CV-60), in the mid-to late 1980s.", by Unknown authorUnknown author, 1980, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Airplane: "First successful flight of the Wright Flyer, by the Wright brothers. The machine traveled 120 ft (36.6 m) in 12 seconds at 10:35 a.m. at Kill Devil Hills, North Carolina. Orville Wright was at the controls of the machine, lying prone on the lower wing with his hips in the cradle which operated the wing-warping mechanism. Wilbur Wright ran alongside to balance the machine, and just released his hold on the forward upright of the right wing in the photo. The starting rail, the wing-rest, a coil box, and other items needed for flight preparation are visible behind the machine. This is described as "the first sustained and controlled heavier-than-air, powered flight" by the Fédération Aéronautique Internationale, but is not listed by the FAI as an official record.", by John T. Daniels, 1903, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Alcohol fermentation: "Philistine pottery קרמיקה פלשתית From Tel Eton פך בירה מעוטר בציפורים, דגים ומוטיבים גיאומטריים, תל עיטון המאה ה-12 לפני הספירה", by Hanay, 2012, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Alcohol thermometer: "An alcohol-in-glass thermometer from the Taylor brand, this one is in the hottest room of the house, this specific room seems to have bad thermal insulation, this thermometer has a +2°C temperature difference to the actual temperature, so even though it's saying its 36°C, the room temperature is actually 34°C,", by Couch-scratching-cats, 2021, licensed under CC BY 2.5, via Wikimedia Commons. View source. View in tree.
• Alembic: "Alambic in einer mittelalterlichen Handschrift Sonstiges: ...", by The original uploader was Makemake at German Wikipedia., 2006, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• AlexNet: "AlexNet block diagram", by Zhang, Aston and Lipton, Zachary C. and Li, Mu and Smola, Alexander J., 2023, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Alphabet with vowels: "Early Greek alphabet painted on the body of an Attic black-figure cup.", licensed under CC BY 2.5, via Wikimedia Commons. View source. View in tree.
• Alternating current: "Types of electric current", by Zureks, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Aluminium: "Tovarna glinice in aluminija Kidričevo - kupi aluminija.", by Unknown authorUnknown author, 1968, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Amate: "Huex codex 1a loc.jpg", licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Amphetamine: "Skeletal formula of amphetamine. Created with ChemDoodle 8.1.0 and Adobe Illustrator CC 2015.", by Vaccinationist, 2016, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Amphora: "Banpo amphora.jpg", by Sgnpkd, 2016, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Amplifier: "One of the first Audion amplifiers built by the inventor of the Audion vacuum tube, Lee De Forest, around 1914. The Audion, the first triode, was the first electronic tube that was able to amplify. Although invented in 1906, the amplifying ability of the Audion was not recognized until 1911-1912, so this was one of the first amplifiers. It appears in a paper by De Forest demonstrating to his fellow engineers that the Audion was not just a radio detector but also had the ability to amplify a signal. This is a three-stage transformer coupled audio amplifier. The Audion bulbs are visible on the front. Audions were always mounted upside-down, with the fragile filament loop hanging down, to prevent it from sagging when hot and touching the grid. Next to each tube are two rotary switches, one to control the filament current and one the plate voltage. The plate voltage between 15 and 40 volts, had to be carefully controlled. The primitive Audion was not completely evacuated, but had some gas in the tube, so if the plate voltage exceeded about 40 volts the gas would break down and ionize, emitting a "blue glow" discharge; which could damage the tube. The tube had a voltage gain of up to 5, so this amplifier had a maximum gain of about 125.", by Lee De Forest, 1914, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Amplitude modulation: "One of the earliest vacuum tube radiotelephone transmitters, built by German scientist Alexander Meissner in 1913. In a historic test in June 1913, Meissner used it to transmit voice 36 km (24 mi) from Berlin to Nauen, Germany. It used a mercury vapor triode vacuum tube (large tube visible) developed beginning in 1906 (approximately at the same time as De Forest's Audion tube) by Austrian engineers Robert von Lieben and Eugen Riesz. The large Lieben-Riesz tube (right) was used in the Meissner oscillator transmitter circuit which he had developed earlier that year, while the receiving circuit used a smaller Fleming valve (left). It transmitted on a wavelength of 600 m (500 kHz) with an output power of 12 W with 440 V on the plate, modulated with a carbon microphone in the antenna lead. H. J. Round noted that when the Leiben tube was used at such power levels, the tube lasted only 10 minutes before the filament burned out due to bombardment by mercury ions.", by Alfred N. Goldsmith, 1917, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Analog computer: "Main w:en:Antikythera mechanism fragment (fragment A). The mechanism consists of a complex system of 30 wheels and plates with inscriptions relating to signs of the zodiac, months, eclipses and pan-Hellenic games. The study of the fragments suggests that this was a kind of astrolabe. The interpretation now generally accepted dates back to studies by Professor w:en:Derek de Solla Price, who was the first to suggest that the mechanism is a machine to calculate the solar and lunar calendar, that is to say, an ingenious machine to determine the time based on the movements of the sun and moon, their relationship (eclipses) and the movements of other stars and planets known at that time. Later research by the Antikythera Mechanism Research Project and scholar Michael Wright has added to and improved upon Price's work. The mechanism was probably built by a mechanical engineer of the school of Posidonius in Rhodes. Cicero, who visited the island in 79/78 B.C. reported that such devices were indeed designed by the Stoic philosopher Posidonius of Apamea. The design of the Antikythera mechanism appears to follow the tradition of Archimedes' planetarium, and may be related to sundials. His modus operandi is based on the use of gears. The machine is dated around 89 B.C. and comes from the wreck found off the island of Antikythera. National Archaeological Museum, Athens, No. 15987.", by No machine-readable author provided. Marsyas assumed (based on copyright claims)., 2005, licensed under CC BY 2.5, via Wikimedia Commons. View source. View in tree.
• Analog optical disc: Patent drawing from Google Patents. View source. View in tree.
• Analytical engine: "This was the first fully-automatic calculating machine. British computing pioneer Charles Babbage (1791-1871) first conceived the idea of an advanced calculating machine to calculate and print mathematical tables in 1812. This machine, conceived by Babbage in 1834, was designed to evaluate any mathematical formula and to have even higher powers of analysis than his original Difference engine of the 1820s. Only part of the machine was completed before his death in 1871. This is a portion of the mill with a printing mechanism. Babbage was also a reformer, mathematician, philosopher, inventor and political economist.", by Charles Babbage, 1871, licensed under CC BY-SA 2.0, via Wikimedia Commons. View source. View in tree.
• Anchor escapement: "The anchor and escape wheel of a late nineteenth century clock (the plate that normally holds the other end of the pinions has been removed for clarity). The crutch and fork attached to the anchor shaft that drives the pendulum, and the pendulum itself, are mounted behind the back plate of the movement.", by Timwether, 2008, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Anemometer: "The Robinson anemometer", by photographer: Archival Photograph by Mr. Sean Linehan, NOS, NGS, 1899, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Aniline: "Ball-and-stick model of aniline as found in the crystal structure. X-ray crystallographic data from Acta Cryst. (1982). B38, 640-643. Model constructed in CrystalMaker 8.1. Image generated in Accelrys DS Visualizer.", by Ben Mills, 2009, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Animal-driven rotary mill: "Horse mill 045493.jpg", licensed under Copyrighted free use, via Wikimedia Commons. View source. View in tree.
• Anode ray: "Anode ray (kanal ray) tube.", by Kkmurray, 2011, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Anthrax vaccine: "Anthrax toxin protective antigen (fragment) heptamer + 14 Ca (green), Bacillus anthracis", by Deposition authors: Lacy, D.B., Wigelsworth, D.J., Melnyk, R.A., Collier, R.J.; visualization author: User:Astrojan, 2016, licensed under CC BY 4.0, via Wikimedia Commons. View source. View in tree.
• Antimony: "Antimony crystal, 2 grams, 1 cm.", by Unknown authorUnknown author, licensed under CC BY 3.0, via Wikimedia Commons. View source. View in tree.
• Aqueduct: "This is a photo of a monument which is part of cultural heritage of Italy. This monument participates in the contest Wiki Loves Monuments Italia 2019. See authorisations.", by Maurizio Moro5153, 2017, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Arc lamp: "Close-up of a 15KW Xenon short-arc lamp. See also end view.", by I attest that I am the copyright holder for this image and I release it for use under the Creative Commons 2.5 license, provided that proper attribution of my copyright is made. - Atlant 19:15, 26 August 2005 (UTC), 2005, licensed under CC BY 2.5, via Wikimedia Commons. View source. View in tree.
• Arcade video game: "Nutting ComputerSpace-Blue.JPG", licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Arch dam: "Morrow Point Dam", by Nationalparks at en.wikipedia, 2006, licensed under CC BY-SA 2.5, via Wikimedia Commons. View source. View in tree.
• Archimedes' screw: "VitruviusTenBooksMHMorgan1914p296.jpg", licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Archipendulum: "Waagenscheit (Setzwaage); Wirtschaftsgebäude Wurzer (TKK 144159), Außervillgraten, Winkeltal 114, Bezirk Lienz, Osttirol, Österreich, EU", by Naturpuur, 2022, licensed under CC BY 4.0, via Wikimedia Commons. View source. View in tree.
• Ard plough: "Maler der Grabkammer des Sennudem 001.jpg", by Painter of the burial chamber of Sennedjem, 1200, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Argand lamp: "Portrait of James Peale", by Charles Willson Peale, 1822, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Argon: "Spectrum = gas discharge tube: the noble gas: argon Ar. Used with 1,8kV, 18mA, 35kHz. ≈8" length.", by Alchemist-hp (talk) (www.pse-mendelejew.de), 2006, licensed under GFDL 1.2, via Wikimedia Commons. View source. View in tree.
• Arithmetic mean: "Under the assumption that the bar can be ignored, the arithmetic mean can be visualised as the position of the triangle to balance the seesaw with the balls.", by Maphry, 2019, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Arithmometer: "Arithmometer built around 1887. At bottom-left is a separate image of the delicate brass lettering (taken from another arithmometer of the same vintage", by Ezrdr, 2009, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Armed car: "The Simms "Motor Scout" Automobile Club Show, Richmond, 17-24 June 1899 Scanned, and displayed with their consent, from the library of Veteran Car Club of Great Britain", by Iliffe Press, 1899, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Armillary sphere (China): "​性命圭旨 周天璇璣圖", by 尹真人, 2017, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Armillary sphere (Greece): "Sphère armillaire de l'Encyclopédie de Diderot et D'Alembert", by Graveur : Benard, 1767, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Armoured car: "Simms_War_Car_at_the_Crystal_Palace_London_April_1902", by AnonymousUnknown author, 1902, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Armstrong gun: "Sagahan_Armstrong_gun_used_at_the_Battle_of_Ueno_against_the_Shogitai_1868", by AnonymousUnknown author, 1868, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Arquebus and matchlock: "Great arquebus for two shooters, Maximilian's Book of Armaments.", by Jörg Kölderer., 1502, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Arrow-firing catapult: "Gastraphetes Biton's (double missile) artistic reconstruction suggested by Schramm's and Marsden's interpretations.", by Ferruggia Aldo, 2013, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Arsenic: ";Description: Elemental arsenic — mineral specimen.", by Arsen_1.jpg: Original uploader was Tomihahndorf at de.wikipedia derivative work: Materialscientist (talk), 2009, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Arsenical bronze: "This small image follows the Sihing iconography- gem radiance, short mantle, "vajrasana," right hand on the knee. It has few if any of the stylistic qualities of the 15th-16th century manifestations of the Sihing, however. The treatment of the facial features may appear to have a folksy quality, but nevertheless the sculptor is in control of the modeling and quite capable of deciding when a straighforwardly graceful curve is in order and when something more quirky is preferable.", by Anonymous (Thailand)Unknown author, 1750, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Articulated tram: "A second-generation articulated tram - probably Articulated #2, later numbered 4001 - in 1913. This version had a much lower step on the center section than the first articulated car.", by Unknown authorUnknown author, 1913, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Artificial neural network: "330-PSA-80-60 (USN 710739): Experimental Machine Able To Identify Letters of Alphabet Announced By Navy. This photo shows the Mark I Perceptron, an experimental machine which can be trained to automatically identify objects or patterns, such as letters of the alphabet. Originated by Dr. Frank Rosenblatt, a psychologist who is in charge of the program at Cornell Aeronautical Laboratory, Buffalo, New York, Mark I is an electromechanical device consisting basically of a “sensory unit” of photocells which contain the machine’s memory, and response units which visually display the machine’s pattern recognition response. The machine is generally trained by placing the test patterns, which could be letters of the alphabet of a single-type face, in the view field of the perceptron’s photoelectric cell “eye.” When the machine incorrectly identifies a pattern or letter, the trainer forces it to respond correctly by means of an electrical control. When the training is completed the letters of the particular type face can then be shown to the machine’s eye, and it will correctly identify the letters without error. When the recognition problem has been complicated by adding letters of a different type face, the machine has been correct 85 percent of the time. The perceptron has particular potential use in the processing of non-numerical information for the solution of scientific, engineering, and military problems. The perceptron research program is sponsored by the Office of Naval Research with the assistance from Rome Air Development Center, Rome, New York, of the Air Research and Development Command. Photograph released June 24, 1960. (8/25/2015).", by National Museum of the U.S. Navy, 2015, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Artificial refrigeration: "RSS Refrigerator electronics and electronics", by N-Lange.de, 2009, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Artificial satellite: "Музей космонавтики и ракетной техники (в Иоанновском равелине Петропавловской крепости). Первый в мире искусственный спутник Земли", by Andrey Butko, 2008, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Asbestos (industrial use): "Asbestos (tremolite) silky fibres on muscovite from Bernera, Outer Hebrides. Photograph taken at the Natural History Museum, London. Background Removed.", by Aramgutang, 2005, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Aschheim-Zondek pregnancy test: "Мышь домовая", by George Shuklin (talk), 2008, licensed under CC BY-SA 1.0, via Wikimedia Commons. View source. View in tree.
• Aspartame: "aspartame; Asp-Phe methyl ester", by Yikrazuul, 2008, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Aspirin: "Bottle with aspirin, 1899. from Bayer Archives", by Bayer AG, 2011, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Astrolabe: "Planispheric Astrolabe", by Khalili Collections, licensed under CC BY-SA 3.0 igo, via Wikimedia Commons. View source. View in tree.
• Atmospheric diving suit: "Tritonia Lusitania 1935.jpg", licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Atmospheric railway: "Aeromóvel de Porto Alegre", by Paulo rsmenezes, 2013, licensed under CC BY-SA 3.0 br, via Wikimedia Commons. View source. View in tree.
• Atomic bomb: "Mushroom cloud of 'Gadget' over Trinity, seconds after detonation", by United States Department of Energy, 1945, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Atomic clock: "Louis Essen and J. V. L. Parry standing next to the world's first caesium atomic clock, developed at the UK National Physical Laboratory in 1955.", by National Physical Laboratory, 1955, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Attention mechanism: "Left (black) part is the autoencoder. Middle (red) part is the Attention unit. Right (grey & colored) is the data calculated. Subscript shows examples of vector sizes, except for i-1 which shows time step.", by Numiri, 2021, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Aulos: "Aulos (double reedpipes or double clarinets), from Attic red-figure cup, Banquet Euaion Louvre G467 n2, 460 BC–450 BC.", by unknown artist, ancient Greece photographer Jastrow (released to Wikimedia Commons under tag PD-self, 2008, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Aurignacian stone tool: "Double edged Scraper on blade - 3 views of the same object.", licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Autochrome: "Stereograph; Autochrome; Transparencies", by Auguste Lumière / Louis Lumière, 1896, licensed under CC0, via Wikimedia Commons. View source. View in tree.
• Autogyro: "Juan de la Cierva C.6 autogyro", by Unknown authorUnknown author, 1924, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Automated external defibrillator: "Modern AED Automated external defibrillator", by VoLid27, 2025, licensed under CC0, via Wikimedia Commons. View source. View in tree.
• Automated insulin delivery system: "A display demonstrating a hybrid closed loop insulin delivery system ('artificial pancreas') at Thackray Museum of Medicine", by Museumjack, 2024, licensed under CC BY 4.0, via Wikimedia Commons. View source. View in tree.
• Automatic flour mill: "Automated mill for processing grain designed by American inventor Oliver Evans (1775-1819)", by Illustration by James Poupard from "The young mill-wright & miller's guide : in five parts, embellished with twenty five plates" by Oliver Evans, of Philadelphia. Philadelphia : Printed for, and sold by the author, 1795., 1795, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Automatic loom: "Métier de Vaucanson CNAM-IMG 0528-2.jpg", licensed under CC BY-SA 2.0 fr, via Wikimedia Commons. View source. View in tree.
• Automatic machine gun: "Maxim machine gun, with thanks to the Georgian National Museum for allowing photography", by Jonathan Cardy, 2012, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Automatic milking system: "Vollautomatisches Melksystem für Kühe; Hersteller: Merlin (Fullwood Packo Gruppe)", by User:Mattes, 2010, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Automatic rice cooker: "保温機能はまだない。", by 投稿者によるスキャン, 2020, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Automatic telephone exchange: "An example of a stepping switch or uniselector assembly. This item is in the collection of the Musée des Arts et Métiers, Paris.", by Brock Craft / Thatbrock at en.wikipedia, 2006, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Automatic teller machine: "London", by Philafrenzy, 2017, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Automatic transmission: "A 1939-56 Hydra-Matic Drive transmission at the Ypsilanti Automotive Heritage Museum in Ypsilanti, Michigan (United States).", by Michael Barera, 2015, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Automobile: "1885Benz.jpg", licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Avvisi: "Periodical hand-writing newssheet with news from Anntwerp of 23 Dec 1663, Cologna, Vienna, Roma, Venezia", by A ntv, 2019, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Backpropagation: "Figure 4 from Andreas Maier, Christopher Syben. Tobias Lasser. Christian Riess. "A gentle introduction to deep learning in medical image processing". Zeitschrift für Medizinische Physik Volume 29, Issue 2, May 2019, Pages 86-101. https://www.sciencedirect.com/science/article/pii/S093938891830120X#fig0010 Please reference this article, if you reuse this figure. Original Caption: Graphical overview of back-propagation using layer derivatives. During the forward pass, the network is evaluated once and compared to the desired output using the loss function. The back-propagation algorithm follows different paths through the layer graph in order to compute the matrix derivatives efficiently.", by Andreas Maier, 2019, licensed under CC BY 4.0, via Wikimedia Commons. View source. View in tree.
• Backstaff: "Davis quadrant-MnM 11 NA 97-IMG 5987-black.jpg", by Rama, 2016, licensed under CC BY-SA 3.0 fr, via Wikimedia Commons. View source. View in tree.
• Bagpipes: "Medieval Bagpiper at Monastery of Santes Creus, Catalonia, Spain, constructed between 1174 and 1225.", by Kriegerkalle, 2007, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Balance scale: ""This is an excellent example of one of the many fine vignettes (illustrations) from the Book of the Dead of Hunefer. The scene reads from left to right. To the left, Anubis brings Hunefer into the judgement area. Anubis is also shown supervizing [sic] the judgement scales. Hunefer's heart, represented as a pot, is being weighed against a feather, the symbol of Maat, the established order of things, in this context meaning 'what is right'. The ancient Egyptians believed that the heart was the seat of the emotions, the intellect and the character, and thus represented the good or bad aspects of a person's life. If the heart did not balance with the feather, then the dead person was condemned to non-existence, and consumption by the ferocious 'devourer', the strange beast shown here which is part-crocodile, part-lion, and part-hippopotamus. However, as a papyrus devoted to ensuring Hunefer's continued existence in the Afterlife is not likely to depict this outcome, he is shown to the right, brought into the presence of Osiris by his son Horus, having become 'true of voice' or 'justified'. This was a standard epithet applied to dead individuals in their texts. Osiris is shown seated under a canopy, with his sisters Isis and Nephthys. At the top, Hunefer is shown adoring a row of deities who supervise the judgement." A more detailed explanation of the scene can be found in the public domain The Book of the Dead, by E. A. Wallis Budge.[1]", by Hunefer, 1275, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Balance spring: "Original image description from the Deutsche FotothekUhr & Uhrwerk", 1676, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Balance wheel: "One of pages Tractatus Astrarii", by Giovanni Dondi dall'Orologio, 2012, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Ballistic missile: "V2-Rocket in the Peenemünde Museum", by AElfwine, 2004, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Ballistic missile submarine: "A Soviet submarine (Zulu Class Submarine, project 611) in the IJ, near the NDSM docks in Amsterdam, the Netherlands", by Anrie, 2008, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Ballpoint pen: "John J. Loud's patent of the ballpoint pen, 1888", by Unknown authorUnknown author, 1888, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Banknote seal: "A Ming Dynasty (about 400, 500 years ago) banknote (paper-based, printing)", by Buhuzu, 2009, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Barbat: "Gandhara Siddhatha Playing A Lute, photograph by Ken Kawasaki at the Indian Museum, Kolkata. Sculpture kept at the Indian Museum in Calcutta. From museum sign: "The Grey Schist or slate stone sculptures hail mainly from the region lying between Eastern Afghanistan and Northern Pakistan (Peshwar and Rawalpindi districts) and belong to the Gandhāra School which flourished from about the 1st century B.C. to the 6th century A.D. Stucco and teracotta were also used as media from about the 3rd century A.D. The art was at its zenith under the patronage of the Kuṣaṇ kings."", by Original artist unknown sculptor 1st through the 7th century A.D., photographer of sculpture was Ken Kawasaki., 2011, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Barbed wire: Patent drawing from Google Patents. View source. View in tree.
• Barium: "Elementares Barium unter Argon Schutzgas / Pure barium in protective argon gas atmosphere.", by Matthias Zepper, 2005, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Barometer: "Torricelli.jpg", licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Baroque guitar: "Jan Vermeer van Delft 013.jpg", by Johannes Vermeer, 1670, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Barrel: "Barrels2.jpg", by C. G. P. Grey, 2004, licensed under CC BY 2.0, via Wikimedia Commons. View source. View in tree.
• Basic oxygen steelmaking: "Sauerstoff Blaskonverter bei ThyssenKrupp in Duisburg", by Katpatuka 17:42, 21. Mai 2009 (CEST), 2009, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Bathyscaphe: "Title: Earth, sky, and sea Identifier: earthskysea00picc (find matches) Year: 1956 (1950s) Authors: Piccard, Auguste, 1884-1962 Subjects: Trieste (Bathyscaphe); Balloons Publisher: New York, Oxford University Press Contributing Library: MBLWHOI Library Digitizing Sponsor: Boston Library Consortium Member Libraries View Book Page: Book Viewer About This Book: Catalog Entry View All Images: All Images From Book Click here to view book online to see this illustration in context in a browseable online version of this book. Text Appearing Before Image: ' Text Appearing After Image: The FNRS Note About Images Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original work.", by Piccard, Auguste, 1884-1962, 1956, licensed under No restrictions, via Wikimedia Commons. View source. View in tree.
• Bayer process: "Bayer-process in Aluminium manufacturing", by Bayer-Verfahren.svg: Andreas Schmidt. The original uploader was AndreasPSchmidt at German Wikipedia.. Later version(s) were uploaded by Matloi at de.wikipedia. derivative work: Hans Erren (talk), 2010, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Beaufort scale: "Beaufort scale image", by United States National Weather Service, 2007, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Bed: "The exquisite, gilded bier on which Egyptian pharaoh Tutankhamun's nest of coffins rested, within his Sarcophagus. It is now on display at the Cairo Museum. This picture was originally taken in 2004 by Hans Ollermann. The following notes are taken from Howard Carter's index card : 253.A. WOODEN BIER POSITION: Under outer coffin (253). Resting on bottom of Sarcophagus. DIMENSIONS: L. 221; W. 85; H. 26.5, cents. DESCRIPTION: Heavy wooden bed-shaped bier, gesso gilt, having within outer framework an imitation webbing, resembling much the string mesh of the Sudanese Augaûl. On the front two heads of lions, on the back tails of lions; the legs, in like manner, represent the fore and hind feet of a lion. The head is of concave form to fit and receive the convex bottom of the anthropoid outer coffin. The under part of the imitation mesh webbing is varnished with black resin. REMARKS: Cleaned with warm water & ammonia, consolidated with paraffin wax.", by Hans Ollermann, 2004, licensed under CC BY 2.0, via Wikimedia Commons. View source. View in tree.
• Beekeeping: "Mesolithic rock painting of a honey hunter harvesting honey and wax from a bees nest in a tree. At Cuevas de la Araña en Bicorp. (Dating around 8000 to 6000 BC)", by Achillea, 2007, licensed under GPL, via Wikimedia Commons. View source. View in tree.
• Beet sugar factory: "Engraving depicting the inside of a French sugar beet mill c. 1843. Published in French magazine L'Ilustration Journal Universel, 13 May 1843 issue.", by Published in French magazine L'Illustration Journal Universel, 1843, 1843, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Bergius process: "Coal bunker, ruins of the German synthetic petrol plant (Hydrierwerke Pölitz Aktiengesellschaft) in Police, Poland", by Remigiusz Józefowicz, 2007, licensed under CC BY-SA 2.5 pl, via Wikimedia Commons. View source. View in tree.
• Beryllium: "Beryllium, >99 % pure, crystalline big fragment >140 g", by Alchemist-hp = Alchemist-hp (pse-mendelejew.de), 2008, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Bessemer process: "Bessemer converter.jpg", licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Beta blocker: "Chemical structure of propranolol — a widely used β-blocker.", by Margoz, 2006, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Bidet: "Boilly La Toilette intime ou la Rose effeuillée.jpg", by Louis-Léopold Boilly, 1790, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Bidriware: "his flat-bottomed hookah base is embellished with inlaid silver sheet and silver wire (tehnishan and tarkashi techniques, respectively). The primary decoration on the vessel sides and in an arcade on the neck is the Mughal dynastic leitmotif of stylized poppy plants (Papaver somniferum), which may suggest that the vessel was commissioned or intended for the Mughal market. The supplementary decoration consists of alternating bands of vegetal and geometric motifs. Chevrons encircle the neck on a ring molding below the larger projecting molding used for grasping or carrying the vessel. There are three bands of crenulation-like foliage, an elegant scrolling poppy vine on the shoulder, and a simplified scroll of stylized flowers and leaves on the base. Flat-bottomed hookah bases presumably made of the zinc-based alloy known as bidri ware, or alternatively perhaps made of brass with a lac ground, are documented in Indian painting by the late 17th century. Prior to their development, hookah bases were generally spherical and needed support rings to keep them upright. By the middle of the 18th century, they had become exceedingly common in painting and extant examples.", by Natasha Khaitan, 2023, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Bimetallic strip: "Bobina Bimetálica Utilizada em Termostatos", by Shorenster, 2008, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Bimetallic thermostat: "Andrew Ure's Bi-Metallic Thermostat", by Michael Osman, 2018, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Binocular microscope: "Ernst Abbe meets Horatio S. Greenough, an American biologist. Of course, they cannot help talking shop. Before long, the discussion is focused on a seemingly utopian idea: the construction of a stereoscopic microscope. Utopian? The idea is born under a lucky star. The American visitor draws a promising sketch on a sheet of paper. That's it. Around the turn of the year, Greenough's invention has taken shape as a ZEISS product: the first stereomicroscope ever.", by ZEISS Microscopy from Germany, 2012, licensed under CC BY-SA 2.0, via Wikimedia Commons. View source. View in tree.
• Binomial nomenclature: "Table of the Animal Kingdom (Regnum Animale) from Carolus Linnaeus's first edition (1735) of Systema Naturae. Text: I. Quadrupedia II. Aves III. Amphibia IV. Pisces V. Insecta VI. Vermes. (Subdivision first column Quadrupedia): Anthropomorpha (Man, apes, sloth), Ferae (wild animals), Glires (= mice), Jumenta (pack animals), Pecora (cattle) and Paradoxa.", by Carl Linnaeus, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Bipolar junction transistor: "This is a silicon NPN grown-junction transistor of type ST2010, manufactured in 1961.", by Nixiebunny at English Wikipedia, 2010, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Bireme: "This Phoenician warship was depicted by Assyrians in their palace of Niniveh. It is a bireme (dieris/Greek διήρης), with two levels of oars. Shields are fastened around the superstructure, as on the fortifications of some city walls. The pointed bow is either a ram, for holding enemy ships, or a form of cutwater. WA 124772 British Museum.", by No machine-readable author provided. World Imaging assumed (based on copyright claims)., 2005, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Bismuth: "The chemical element bismuth as synthetically made crystals. The surface is oxide free. Additionally, a high purity (99.99 %) 1 cm3 bismuth cube for comparison.", by Alchemist-hp (talk) (www.pse-mendelejew.de), 2010, licensed under FAL, via Wikimedia Commons. View source. View in tree.
• Bitumen: "Natural formed Bitumen collected at the Dead Sea shore", by Daniel Tzvi, 2007, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Blast furnace: "Chinese iron workers smelting iron ore to make pig iron and wrought iron in 16th century. The left half of the illustration shows a fining process, while the right half displays men operating a blast furnace. The fining process uses calcium oxide which is spread over the raw iron and stirred in (撒潮泥灰) (see Don. Wagner analysis): this is a specific fining process, very different form later chinese puddling processes. This illustration is an original from the Tiangong Kaiwu encyclopedia printed in 1637, written by the Ming Dynasty encyclopedist Song Yingxing (1587-1666). Picture taken on the web from at: http://donwagner.dk/MingFe/MingFe.html The picture also appears in Figure 14-10 on page 250 of E-tu Zen Sun and Shiou-Chuan Sun's translation of the Tiangong Kaiwu encyclopedia (Pennsylvania State University Press, 1966).", licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Blockchain: "The main chain (black) consists of the longest series of blocks from the genesis block (green) to the current block. Orphan blocks (purple) exist outside the main chain.", by original file: Theymos from Bitcoin wiki vectorization: User:Razorbliss rotation: Own work, 2011, licensed under CC BY 3.0, via Wikimedia Commons. View source. View in tree.
• Bloomery: "Étouars, Dordogne. Journée fer et forges au mois d'août 2013. Bas fourneau à usage unique.", by Traumrune, 2013, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Blu-ray: "Back of a Blu-ray Disc. I took this.", by File:BluRayDiscBack.png: Cdnomad at English Wikipedia derivative work: Georgfotoart, 2024, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Blue laser: "Beam splitters. Peterborough - UK", by Nikk, 2015, licensed under CC BY 2.0, via Wikimedia Commons. View source. View in tree.
• Blue LED: "Blue light emitting diodes (Blue LED)", by Gussisaurio, 2010, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Blueprint: "An experimental cyanotype of an engraving of a lady with a harp, by Sir John Herschel (1792-1871), 1842.", by John Herschel, 1842, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Bluetooth: "A Bluetooth headset for mobile phones. Camera: FUJIFILM FinePix S7000 Exposure: 1/80 sec. Focal Length: 8mm Aperture: F/2.8 ISO: 400", by Ed g2s, 2004, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Boat: "The Pesse canoe is believed to be the world's oldest known boat. It is made from a piece of trunk of the Scots pine (Pinus silvestris). With the help of fire, this piece of trunk, with the exception of the front and back ends, has been hollowed out. A thin layer of charred wood is still present in many places on the inside of this hollowed-out tree trunk. The exterior also shows clear traces of fire.", 8040, licensed under CC BY 3.0, via Wikimedia Commons. View source. View in tree.
• Bobbinet machine: "Bobbinet framework A- Warp beam B- Lace take up roller C- Represents the combs or guides, with two brass-bobbins in their carriers. There were two as the technology could not produce a brass-bobbin 1/20inch (0.05) thick but 1/10 in (0.10) was do-able, so two ends shared one comb. The combs in were integral to the front comb bar and rear comb bar, which could shog 1 thread space sideways. The bobbins were propelled by front driver bars and back driver bars which were above the comb bar.(b) Text from Earnshaw 1986, p=70", by E. Lacroix, 1862, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Bolt-action rifle: "Cutaway diagram of a 1870s Swiss Vetterli rifle action", by Unknown authorUnknown author, 1870, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Bomba kryptologiczna: "The Polish Bomba", by Marian Rejewski, 2013, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Bombe (cryptology): "Wartime picture of a Bletchley Park Bombe", by Unknown authorUnknown author, 1945, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Bone tool: "Awl on bone sliver - Different views of the same specimen", licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Boomerang: "Egyptian Artifacts. National Archaeological Museum, Athens, Greece --- "Ομοίωμα ραβδίου σε σχήμα μπούμεραγκ. Οι ευγενείς τα χρησιμοποιούσαν ως όπλο για το κυνήγι των πουλιών στους βάλτους. Είχαν, επιπλέον, τελετουργική και ταφική χρήση. Φαγεντιανή." Αιγυπτιακή συλλογή. Εθνικό Αρχαιολογικό Μουσείο. Αθήνα.", by Tilemahos Efthimiadis from Athens, Greece, 2009, licensed under CC BY 2.0, via Wikimedia Commons. View source. View in tree.
• Borehole drilling: "Borewell digging A borehole is a narrow shaft bored in the ground, either vertically or horizontally. A borehole may be constructed for many different purposes, including the extraction of water, other liquids (such as petroleum) or gases (such as natural gas), as part of a geotechnical investigation, environmental site assessment, mineral exploration, temperature measurement, as a pilot hole for installing piers or underground utilities, for geothermal installations, or for underground storage of unwanted substances, e.g. in carbon capture and storage.", by Vijayanrajapuram, 2017, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Boring machine: "Wilkinson's cylinder boring machine at Bersham, 1775. (model). Plate 22 from The Machine Tool Collection (1966)", by Gilbert, K.R. (Keith Reginald) 1915-1973, 1966, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Boron: "Polycrystalline chunks of rhombohedral β-boron, net 25.5 grams", by James L Marshall, 2013, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Bow and arrow: "Cave painting of a battle between archers, Cueva del Roure, Morella la Vella, Castellón, Valencia, Spain. Dated to the late Mesolithic, dubbed the "earliest surviving image of combat" (although no precise dating is possible). Literature: Keith F. Otterbein, How War Began (2004), p. 72f. Žiga Šmit, "Archery by the Apaches – implications of using the bow and arrow in hunter-gatherer communities", Documenta Praehistorica XLIII (2016), p. 516.", by Eduardo Hernández Pacheco, 1924, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Bow drill: "production de feu par friction à l'aide d'un archet - planchette en lierre et foret en pin", by No machine-readable author provided. 120 assumed (based on copyright claims)., licensed under CC BY 2.5, via Wikimedia Commons. View source. View in tree.
• Boyden turbine: "Sketch of a Boyden Turbine, 1878", by James Emerson - Treatise relative to the testing of waterwheels and machinery, 1878, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Boyle's air pump: "Drawing of Robert Boyle's air pump. It illustrates: a 28.4-litre glass "receiver" (A) connected by a stopcock (N) to a 36-cm-long brass pumping cylinder, through which a padded piston (4) was drawn by a toothed shaft (5). To operate the air pump, first the stopcock was closed, and the piston was cranked down. Then, with the stopcock opened, part of the air in the receiver moves into the cylinder. Then the stopcock was closed, the brass plug (R) removed, and the piston raised, expelling air from the cylinder. As the procedure was repeated, the air pressure in the receiver decreased. (See caption in "Robert Boyle", MB Hall - Scientific American, 1967)", by Robert Boyle, 1661, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Brace: "Bohrwinde und Schraubendreherklinge", by M_H.DE, 2009, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Braille: "Brailleskrift.", by Stefan Malmesjö, 2010, licensed under CC BY 2.0, via Wikimedia Commons. View source. View in tree.
• Brainbow: "Mouse neurons labeled with fluorescent tags. Such “color coded” brain cells promise new solutions to formerly intractable problems with resolving closely packed neurons and tracing their axons and dendrites reliably over long distances. It seems unlikely that neural information processing will ever be understood without solving such problems and reconstructing circuits in far more detail that presently possible.", by Stephen J Smith, 2007, licensed under CC BY 3.0, via Wikimedia Commons. View source. View in tree.
• Brake lining: "Brake shoes", by Maly LOLek, 2007, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Bramah lock: "L-Schloss-Brahma.png", licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Brass: "This ewer with geometric and floral designs, exemplifies a group of cast brass ewers, which may belong to the earliest known examples of Islamic metalwork. It is distinguished by its pear-shaped body, elegant palmette handle, and vegetal designs in bold relief.", by Anonymous (Iran)Unknown author, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Bronze bell: "Anhui Provincial Museum, Hefei, 2012. Complete indexed photo collection at www.WorldHistoryPics.com.", by Gary Lee Todd, Ph.D., 2012, licensed under CC0, via Wikimedia Commons. View source. View in tree.
• Bubble chamber: "BubbleChamber-fnal.jpg", licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Bubonic plague vaccine: "Doctor Simmonds injecting his curative serum in a plague patient, during the outbreak of bubonic plague in Karachi, India. Photograph, 1897. Photograph probably by Jalbhoy, R. The lettering is printed on the mount Karachi is a port in the province of Sind (now [1996] Pakistan). It was placed in quarantine in 1882, during the outbreak of bubonic plague which spread from Bombay. The Plague Committee consisted mostly of volunteers, who were organised into parties and were responsible for the segregation and inoculation of various districts Contained in an album of photographs which show the work of the Karachi Plague Committee in 1897 Iconographic Collections Keywords: Karachi Plague Committee (India)", licensed under CC BY 4.0, via Wikimedia Commons. View source. View in tree.
• Bucket chain excavator: "L’excavatrice « Titan » en action aux ballastière de Champagney - 1903 - photographe Pourchez.", by Camille Pouchez, 1903, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Bucket-wheel excavator: "bucket-wheel excavator in Ferropolis, Germany", by Stefan Kühn, 2000, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Bude-Light: ""BUDE LIGHTS, TRAFALGAR-SQUARE - The lanterns for the reception of the Bude Lights to illumine this fine area, exhibit certain novel and meritorious peculiarities of form and construction, which has induced us to engrave them for our columns. The lanterns, four in number, are of an octagonal shape, from the design of Mr. Barry, R.A., and manufactured by Messrs. Stevens and Son, of the Darlington Works, Southwark. They are placed on four large bronze pedestals ; the height of the larger pair, from the base to the bottom of the lamp , is 3 feet six inches,.. These are to be fixed on the massive granite pillars on the south-east and south-west angles of the square. The two smaller ones are... height, 9 feet to the bottom of the lamp. These are destined for the balustrades opposite the National Gallery: the gun metal, of which the whole is composed, is ⅜ of an inch thick. The lamps are to be glazed with flint glass of the substance of an inch, with a 2-inch cut bevel, worked parallel surfaces, and all highly polished. The refraction of light occasioned by these numerous varieties of surface is likely to produce a very brilliant effect". The Illustrated London News, May 3, 1845.", by Uncredited, 1843, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Bulla: "Two clay bullae, one complete and sealed, the other broken with tokens visible, Uruk period. Oriental Institute Museum, Chicago.", by Original: Daderot Derivative work : Zunkir, 2014, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Bulldozer: "Caterpillar D9T", by Shaun Greiner, 2008, licensed under CC BY-SA 2.0, via Wikimedia Commons. View source. View in tree.
• Bulletin board system: "Login Banner of the CBBS", by Aeroid, 2018, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Bullroarer: "I took this picture in the Pitt Rivers Museum in Oxford and release it under the GFDL.", by Throwawayhack at English Wikipedia, 2006, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Bunsen burner: "Een bunsenbrander in het scheikundelokaal", by Sally V, 2016, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Burr mill: "Mlynek.jpg", licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Byzantine lyra: "Byzantine, ivory casket c. 1000 (from Museo Nazionale, Coll. Carrand, No. 26) Kindly donated by Author of http://crab.rutgers.edu/~pbutler/rebec.html", by Paul Butler, 1000, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Cable car: "Etching of Adam Wybe's cable car in Danzig. Artist: Willem Hondius", by Willem Hondius, 1644, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Cable car tram: "Cable Driving Plant, Designed and Constructed by Poole & Hunt, Baltimore, MD. Drawing by P.F. Goist, circa 1882. The powerhouse has two horizontal single-cylinder engines. The lithograph shows a hypothetical prototype of a cable powerhouse, rather than any actual built structure. Poole & Hunt was a major cable industry designer and contractor and manufacturer of gearing, shafting and wire ropes. They did work for cable railways in Baltimore, Chicago, Kansas City and Philadelphia.", by Poole and Hunt Company, 2014, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Cable television: "Collectie / Archief : Fotocollectie Anefo Reportage / Serie : [ onbekend ] Beschrijving : Siemens Nederland heeft kabelsysteem ontwikkeld waarmee 30 kanalen door een kabel kunnen worden doorgestuurd Datum : 20 maart 1981 Locatie : Zoetermeer, Zuid-Holland Trefwoorden : KABELTELEVISIE Instellingsnaam : Siemens Fotograaf : Dijk, Hans van / Anefo Auteursrechthebbende : Nationaal Archief Materiaalsoort : Negatief (zwart/wit) Nummer archiefinventaris : bekijk toegang 2.24.01.05 Bestanddeelnummer : 931-3837", by Hans van Dijk for Anefo, 1981, licensed under CC0, via Wikimedia Commons. View source. View in tree.
• Caffeine: "Fibrous caffeine crystals as viewed by dark field light microscopy. Points where nucleation occurred are clearly visible; nucleation occurred at the points the fibrous crystals radiate out from. 1.559 μm per pixel, the entire image covers an area of approximately 11 x 7 mm.", by Zephyris, 2010, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Calcium: "Pure calcium in a protective argon atmosphere", by Matthias Zepper, 2007, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Calcium carbide production: "CaC2", by Ondřej Mangl, 2007, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Calculus: "Graphs for Leibniz, Gottfried Wilhelm von: Nova methodus pro maximis et minimis, Acta Eruditorum, 1684 October, p. 466", by Leibniz, Gottfried Wilhelm von, 1684, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Calico: "Calico used to fabicate a promotional shopping bag. Scale in cm.", by Clem Rutter, Rochester, Kent., 2010, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Caliper: "​东汉铜卡尺。扬州邗江甘泉乡姚湾村汉墓出土。", by 三猎, 2016, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Calotype: "Henry Fox Talbot - The Building of Nelson^s Column - B2018.20.3 - Yale Center for British Art.jpg", by William Henry Fox Talbot, 1843, licensed under CC0, via Wikimedia Commons. View source. View in tree.
• Calutron: "Alpha I racetrack, Y-12 Uranium 235 electromagnetic separation plant, Manhattan Project, Clinton Engineer Works, Oak Ridge", by James Edward Westcott, 1950, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Cam: "line art drawing of cam.", by Pearson Scott Foresman, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Camera lucida: "Camera Lucida in use drawing small figurine", by Unknown authorUnknown author, 2011, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Camera obscura: "The camera obscura principle as illustrated in James Ayscough's A short account of the eye and nature of vision (1755 fourth edition)", by James Ayscough, 1755, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Camera phone: "CP+ 2011: 1999 Kyocera VP-210", by Morio, 2011, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Campbell–Stokes recorder: "Heliograph (Sonnenscheinautograph, Sonnenscheinmessgerät), Wendelstein", by Rolf Gebhardt, 2002, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Can opener: "Yates can opener. Yates drawing (left) originates from http://www.researchpod.co.uk/pdf/lifting_the_lid_on_the_tin_can_opener.pdf", by own work, 2009, licensed under CC BY 3.0, via Wikimedia Commons. View source. View in tree.
• Can opener with serrated wheel: "Apriscatole "Star" a due manici e due rotelle di cui una dentata, con funzione di avanzamento, collegata a una farfalla. Sui manici compiono le scritte a incisione 'STAR CAN OPENER COMPANY / SAN FRANCISCO / MADE IN USA' e '1923 - # 218377 / Star / TRADE MARK REGISTERED'.", licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Candle: "This is a photo of a place that is recognized as a heritage site by the Council for Conservation of Heritage Sites in Israel.The site's ID in Wiki Loves Monuments photographic competition is", by Godot13, 2013, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Canning: "Bouteille a conserve époque Appert, collection Jean-Paul Barbier, musée Châlons en Champagne salle Appert", by Jpbarbier Jean-Paul Barbier, 2000, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Cannon: "黑龍江火銃，一二八八年", by Aldermanseven, 2021, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Cantilever bridge: "Quebec Bridge seen from North shore of the Saint Lawrence River", by Martin St-Amant (S23678), 2009, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Capillary action: "Capillary water flow in a brick that is in contact with water at the bottom. The time elapsed after first contact with water is indicated. The brick height is 225 mm. From the weight increase, the estimated porosity is 25%.", by Hankwang, 2011, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Capsule endoscopy: "I produced this image by putting a (used) capsule on the scanner next to a ruler.", by No machine-readable author provided. Euchiasmus assumed (based on copyright claims)., 2006, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Caravel: "Caravela de armada of João Serrão. 1502", by Unknown authorUnknown author, 1566, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Carbide lamp: "Brass carbide lamp by Justrite.", by Scott Ehardt, 2006, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Carbon arc welding: "N.N.Benardosa's patent for a way of arc electric welding "Electrogefest"", by Unknown authorUnknown author, 1887, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Carbon fibers: "Carbon fibre", by Hadhuey at German Wikipedia, 2005, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Carbon microphone: "Western Electric Model 357 double button carbon microphone in 1B housing, used at WFBM, the first radio station in Indianapolis, Indiana, USA, from its founding in 1924. The double button microphone was developed around 1921 by Western Electric and was extremely widely used as a broadcast and recording microphone through the 1920s because it had significantly lower noise and harmonic distortion. It is often called the "ring and spring" micrphone, as it is often seen in period photos with its cover removed. as a small microphone cylinder suspended in the center of a metal ring by springs. Carbon microphones consist of a cell containing carbon granules between two electrodes in contact with a diaphragm, but they have high harmonic distortion because the change in resistance of the carbon is nonlinear, different under compression than under tension. The double button design used two carbon cells in contact with the diaphragm on either side. They were connected to a battery and center-tapped audio transformer in a "push-pull" circuit, which canceled even-order harmonic distortion. The stiff duralumin diaphragm had a small excursion which further reduced distortion and high resonant frequency and air damping which gave it a flatter frequency response. However the cost of this higher fidelity was that it had very low output.", by Original work: Radio_equipment_-_Indiana_State_Museum_-_DSC00410.JPG: Daderot derivative work: Chetvorno, 2014, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Carbon paper: "Carbon paper.jpg", licensed under CC BY-SA 2.5, via Wikimedia Commons. View source. View in tree.
• Carbon-dioxide laser: "continuous wave 50,000 watt carbon dioxide electric discharge coaxial laser [1]. Original caption: "A sergeant operates a 15,000-watt laser. This laser is one of several that are used to evaluate the effects", by Unknown authorUnknown author, 2008, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Carbonated water: "Pneumatic trough, and other equipment, used by Joseph Priestley", by Joseph Priestley (1733-1804), 1775, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Carding: "Picture number:10419132 Credit:Science Museum/Science&Society Picture Library Image Caption: Engraving by Poisson after a painting by Pierre Sonnerat (1748-1814), showing "a man carding raw cotton". (Carding is using a card or comb to clean or disentangle the fibres prior to weaving. Carding is an approximate description for this. The actual word for this profession, according to the author who is uploading it, is Dhunuri in eastern India). Illustration from Sonnerat's 'Voyage aux Indes Orientales et a la Chine, fait par ordre du roi, depuis 1774 jusqu'en 1781' ('Voyage to the East Indies and China, made by order of the king, from 1774 to 1781'), published in 1782. In Collection of: Science & Society Picture Library Subject(s) > Trade & Industry > Textile Industry", by Engraver: Poisson, Painter: Sonnerat, Pierre, 1748-1814, uploader Dr.saptarshi, 1923, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Carnot cycle: "Working principle of Carnot's heat engine.", by Eric Gaba (Sting - fr:Sting), 2006, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Carousel slide projector: "A Kodak Carousel 4400 slide projector with a 140-slide tray in use.", by Steve Morgan, 2016, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Carrack: "سفن برتغالية صقيلة قرب ساحل صخري", by anonymous, 1540, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Carruca: "First farm work of the year, sowing and ploughing and suchlike. The castle in the background is Lusignan. Detail from the calendar Les très riches heures from the 15th century. This is a detail from the painting for March.", by Paul Limbourg, Hermann Limbourg and Jean Limbourg, 1410, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Cartesian coordinate system: "Cartesian coordinates 2D.svg", licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Carvel boat building: "(partial) reconstruction of the Yassiada shipwreck from Byzantine times (7th c.), St. Peter's castle; Bodrum, Turkey", by Georges Jansoone (JoJan, 2007, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Cash register: "National cash register from the end of the 19th century, National History Museum, Sofia.", by Biser Todorov, 2021, licensed under CC BY 4.0, via Wikimedia Commons. View source. View in tree.
• Cassegrain reflector telescope: "Cassegrain telescope.", by Szőcs Tamás Tamasflex, 2009, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Cassette deck: "Advent tape recorder with Dolby B noise-reduction system at the National Museum of American History (ca. 1972, cat. 2014.0318.01). The model 201 was the first deck with Dolby released in North America in 1971 for a price of 280 USD, and sold until 1976 [1]. Advent's first cassette deck, model 200, was made by Nakamichi; the model 201 used an off-the-shelf, heavy-duty transport made by Wollensak and electronics made by Advent themselves.", by Votpuske, 2023, licensed under CC BY 4.0, via Wikimedia Commons. View source. View in tree.
• Cassette tape: "TDK SA90 Type II Compact Cassette", by Thegreenj, 2007, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Cast iron: "Iron Lion of Cangzhou, town of Cangzhou in Hebei Province, China.", by Rolfmueller, 2007, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Cast stone: "This file was uploaded with Commonist.", by Dr. med. Mabuse, 2010, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Castle: "Montbazon - Donjon", by MOSSOT, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Catalan forge: "A Blomary Fire. The cavity of the hearth d … was lined with fire-resisting stone. … The tuyère, b, was placed from seven to eight inches above the bottom of the hearth, and was contrived so that its inclination could be varied at pleasure. The blast was produced either by the "trompe" or by wooden or leather bellows. … The bottom and sides of the "hearth" having been lined with a thick coating of charcoal dust, it was then filled with charcoal, upon which crushed ore was thrown, and kept in place by a dam of charcoal dust (c). … [O]re and charcoal were added from time to time as the work progressed, and sometimes the mass of fuel and ore was heaped up three or four feet.", by William F. Durfee, 1890, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Catalytic converter: "OEM Catalytic Converter on a 1996 Dodge Ram B2500 van. Dual inlets, single outlet. old, and about to be replaced.", by Ahanix1989 at English Wikipedia, 2007, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Catamaran: "Hōkūle`a, a modern Hawaiian wa'a kaulua or voyaging canoe, sailing off Honolulu, photo taken from onboard the Chinese junk Princess Taiping, January 22, 2009.", by HongKongHuey, 2009, licensed under CC BY 2.0, via Wikimedia Commons. View source. View in tree.
• Catapult: "Replica catapult.jpg", licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Cataract surgery: "Couching for cataract. General Collections Keywords: opthalmology; Arnold Sorsby", licensed under CC BY 4.0, via Wikimedia Commons. View source. View in tree.
• Cathode ray: "Beam of cathode rays (electrons) in a demonstration vacuum tube moving in a circle in a magnetic field (cyclotron motion). The electrons are produced by an electron gun at bottom, consisting of a hot cathode, a metal plate heated by a filament so it emits electrons, and a cylindrical metal anode at a high voltage which accelerates the electrons into a beam. The red circular Helmholtz coil partially visible behind the tube generates a horizontal magnetic field that exerts a Lorentz force on the electrons. The force on the electrons is perpendicular to their direction of motion, causing them to bend into a circular path. Cathode rays are normally invisible, but enough air has been left in the tube so that the air molecules glow pink from fluorescence when struck by the fast-moving electrons.", by Sfu, 2008, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Cathode-ray tube: "Drawing of the first cathode ray tube invented by German scientist Ferdinand Braun in 1897. It was a cold cathode tube, developed from the Crookes tube and so did not have a heated filament to produce electrons. Instead it produced electrons by ionization of residual gas in the tube with a high voltage. The tube contains a platinum cathode electrode (right end), an anode electrode consisting of an open tube in the neck to focus the electrons into a narrow beam (center right), a pair of flat deflection plates (center left), and a paper screen (left) painted on the inner side with a fluorescent chemical like zinc sulfide or calcium tungstate. When a high voltage is applied between the cathode and anode, it creates positive ions which are attracted to the negative cathode. When they strike the cathode they knock out electrons (cathode rays) which are accelerated down the tube to the left, through the anode tube, between the deflection plates, and strike the fluorescent screen at the left end, producing a glowing spot. If a second voltage is applied between the deflection plates the electron beam will be repelled by the positive plate and attracted toward the negative plate, so the spot on the end screen will move toward the positive plate.", by Eugen Nesper, 1921, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Cave painting: "Hands at the Cuevas de las Manos upon Río Pinturas, near the town of Perito Moreno in Santa Cruz Province, Argentina. Picture taken by me in 2005.", by Mariano, 2005, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Cavity magnetron: "Magnetron with section removed (magnet is not shown)", by HCRS Home Labor Page, 2005, licensed under CC BY-SA 2.0 at, via Wikimedia Commons. View source. View in tree.
• Celestial globe: "02 10 2024 Photo Paolo Villa-Napoli-mann-Museo Archeologico-FO232559-Arte Romana-Atlante Farnese Atlas-det globo testa-(6374)-marmo", by Paolo Villa, 2024, licensed under CC BY 4.0, via Wikimedia Commons. View source. View in tree.
• Cell: "Original figure legend: "General view of cells in the growing root-tip of the onion, from a longitudinal section, enlarged 800 diameters. a. non-dividing cells, with chromatin-network and deeply stained nucleoli; b. nuclei preparing for division (spireme-stage); c. dividing cells showing mitotic figures; e. pair of daughter-cells shortly after division."", by Edmund Beecher Wilson, 1900, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Cell phone: "A Motorola DynaTAC 8000X from 1984. This phone has an early British Telecom badge and primitive red LED display.", by Redrum0486, 2008, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Cell theory: "HeLa cells stained with Hoechst 33258 stain.", by TenOfAllTrades at English Wikipedia, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Cellophane: "Tons and tons of Solid Easter Bunnies.", by Jackie, 2006, licensed under CC BY 2.0, via Wikimedia Commons. View source. View in tree.
• Cellophane adhesive tape: "A tape dispenser.", by Donmike10 (talk) at en.wikipedia., 2009, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Cellular network: "Simonsen Radiofabrikk (norwegian) 1981 NMT mobile phone set. NMT was the 1981-1992 mobile network standard in Scandinavia, and totally analogous. User equipment weighed several kilos. Telenor, Fornebu, Norway.", by HLundgaard, 2011, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Celluloid: "Old celluloid film rolls. EYE Restauratie-atelier.", by Marcel Oosterwijk from Amsterdam, The Netherlands, 2010, licensed under CC BY-SA 2.0, via Wikimedia Commons. View source. View in tree.
• Cellulose: "Structure of cellulose (chain conformation)", by NEUROtiker, 2007, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Cellulose acetate film: "A 16mm reel of Kodachrome movie film showing shrinking and warpage from vinegar syndrome degradation. Film stock date code is 'plus sign / square' which translates to 1955 vintage. Selection from 'Small Gauge Reel & Film Can Archive' by Daniel D. Teoli Jr.", by Danielteolijr, 2018, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Celsius scale: "A putto showing a thermometer with the old Celsius scale (0°C boiling point of water, 100°C freezing point)", by Jan Wandelaar, 1738, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Central dogma of molecular biology: "An overview of the (basic) central dogma of molecular biochemistry with all enzymes labeled.", by Dhorspool (talk) Daniel Horspool, 2008, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Central processing unit: "A photo of the Intel i9 14900KF CPU from above", by Pstrahl, 2024, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Centrifuge: "19th century centrifuge, held at the Deutsches Apotheken-Museum, Heidelberg", by Kierano, 2008, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Ceramic: "Věstonická Venus at the Mammoth Hunters exhibition in the National Museum in Prague", by che (Please credit as "Petr Novák, Wikipedia" in case you use this outside Wikimedia projects.)guidance: Danny B., 2007, licensed under CC BY-SA 2.5, via Wikimedia Commons. View source. View in tree.
• Chain mail: "Celtic Museum Manching ( Bavaria ). Exhibition "Rome´s unknown borders": Celtic warrior grave (3rd century BC ) from Ciumesti: Fragments of iron chainmail ( District Museum Maramures Baia Mare ).", by Wolfgang Sauber, 2013, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Chain pump: "Water raising device", by Al-Jazari, 1205, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Chain rule: "Chain rule - English version", by Qniemiec, 2025, licensed under CC0, via Wikimedia Commons. View source. View in tree.
• Charcoal: "Pictures of charcoal, a fuel obtained by the slow and incomplete combustion of wood", by Dati Bendo, European Commission, 2020, licensed under CC BY 4.0, via Wikimedia Commons. View source. View in tree.
• Charged-coupled device: "CCD image sensor SONY ICX493AQA 10,14 (Gross 10,75) M pixels APS-C 1.8" 28.328mm (23.4 x 15.6 mm) from module IS-026 from digital camera SONY DSLR-A200 or DSLR-A300 sensor side", by User:Andrzej_w_k_2, 2014, licensed under CC BY 4.0, via Wikimedia Commons. View source. View in tree.
• Chariot: "A vase discovered in southeastern Iran dated to c. 2000-1800 BC shows a warrior riding a chariot pulled by a horse. From the Louvre Museum.", by Mitrayasna, 2023, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Chatbot: "A conversation with the ELIZA chatbot.", by Unknown authorUnknown author, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Chemical vapor deposition: "DC-PECVD system in action. DC plasma (violet) improves the growth conditions for carbon nanotubes in this chemical vapor deposition chamber. A heating element (red) provides the necessary substrate temperature.", by polyparadigm (talk · contribs), 2003, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Chemically strengthened glass: "Gorilla glass screen of a Nokia N8", by Titanas from Athens, Greece, 2010, licensed under CC BY-SA 2.0, via Wikimedia Commons. View source. View in tree.
• Cheque: "A signed check by Gerald Ford while serving as the 38th President of the United States.", by National Museum of American History, 2014, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Chess automaton: "Second chess automata of Leonardo Torres Quevedo at Civil Engineering Faculty museum in Madrid.", by MdeVicente, 2011, licensed under CC0, via Wikimedia Commons. View source. View in tree.
• Chinampa: "reconstrução artificial de chinampas astecas", by JORboney, 2023, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Chinese treasure ship: "Chinese woodblock print, representing Zheng He's ships", licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Chintz: "Chintz fragment with tulips and insects (reportedly found in Japan), Coromandel Coast, India, ca.1700-30. 0.13 x 0.20 m (5″ x 8″). Hand-drawn on cotton cloth using dyes, mordants and resists. Karun Thakar Collection Ben Evans muses on how this fact and its historical significance can be understood through the lens of Indian textiles: For me, this chintz fragment has always loomed larger than its diminutive size since it unites a number of strands of interest in one object. It is a small piece of seemingly unimportant cloth in which, by looking a little deeper, one can see that the lively drawing of tulips and insects is sketched in a manner reminiscent of botanical drawings of the 17th century, when European artists were recording the natural world. These have been copied by Indian artists with a vibrancy that, according to one expert, reflects the tulips seen on VOC export porcelain from the mid-17th century. That in itself is a remarkable instance of trade and design transfer, but the fact that this fragment was found in Japan adds another layer to its story. The HALI Tour to Japan in 2019 revealed the extraordinary reverence paid there to Indian cotton, a fabric that in Britain, and perhaps elsewhere in the West, had lost its lustre and appeal through its ubiquity—indeed the adjective ‘chintzy’ even became a pejorative term. The care taken to preserve the textile and the value attached to its function instils this humble scrap of cloth with new meaning for me and can serve as a metaphor for the appreciation of Indian textiles exported for generations across the world.", by Karun Thakar Collection photo. Work by unknown Coromandel srtisans, 1700, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Chlorine: "Chlorine gas in a sphere", by W. Oelen, 2007, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Chlorofluorocarbons: "Ball and stick model of the dichlorodifluoromethane molecule.", by Ben Mills and Jynto, 2009, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Chocolate: "An image from a vase. A Mayan lord is presented with a bowl of frothing cacao, or chocolate.", by Mayan civilisation, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Chocolate bar: "Green & Black's organic dark chocolate bar (35 grams, 70% cocoa). Sold in the United Kingdom.", by Mx. Granger, 2021, licensed under CC0, via Wikimedia Commons. View source. View in tree.
• Cholera vaccine: "Two ampules of anti-cholera vaccine in devitalised condition on display board, 1892 Wellcome Images", licensed under CC BY 4.0, via Wikimedia Commons. View source. View in tree.
• Chromatography: "Separation of black ink on TLC plate. I took the photo after experimenting with black ink from permanent marker (Stabilo OHPen universal) and ethanol+water mixture as solvent. Source: see Photos contributed by Natrij", by The original uploader was Natrij at English Wikipedia., 2004, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Chromium: "High purity (99.999 % = 5N) chromium crystals, produced by chemical transport reaction through decomposition of chromium iodides, as well as a high purity (99,95 % = 3N5) 1 cm3 chromium cube for comparison.", by Alchemist-hp (talk) (www.pse-mendelejew.de), 2010, licensed under FAL, via Wikimedia Commons. View source. View in tree.
• Chromosome theory of inheritance: "Metaphase chromosomes from a female human lymphocyte, stained with Chromomycin A3, fluorescence microscopy. Made with: Colcemid treatment, hypotonic shock, methanol acetic acid fixation, dropping, air drying, staining.", by Steffen Dietzel, 2006, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Chromosomes: "A gene is a segment of DNA that encodes function. A chromosome consists of a long strand of DNA containing many genes. A human chromosome can be up to 500 Mega-base of DNA and contain thousands of genes.", by Thomas Shafee, 2015, licensed under CC BY 4.0, via Wikimedia Commons. View source. View in tree.
• Chronophotographic gun: "Le Fusil photographique, article d'Étienne-Jules Marey paru dans la Nature n°464 du 22 avril 1882", by Louis Poyet, 1882, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Chronophotography: "The Horse in Motion by Eadweard Muybridge. Noted photographer, Eadweard Muybridge was hired, in 1872, by Leland Stanford a railroad baron and future university founder, to find out if there was moment mid-stride where horses had all hooves off the ground. It took several years but Muybridge delivered having captured a horse, named "Sallie Gardner," owned by Stanford; running at a 1:40 gait over the Palo Alto track, on 19th June 1878. Muybridge used a dozen cameras all triggered one after another with a set of strings.", by Eadweard Muybridge, 1878, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Cigar: "Aztec feast 1.jpg", licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Cigarette: "Cigarette", by Augustus Binu : flickr, 2015, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Cinematograph: "Movie camera called Cinematographe build by Leon Bouly in 1892, Musée des Arts et Métiers, Paris, inventory n°16684-0000-", by Pantoine, 2008, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Cipher disk: "Cipher disc for substitution cipher, manufacturer: Linge, Pleidelsheim (Germany)", by Hubert Berberich (HubiB), 2013, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Circular knitting machine: "Kézi működtetésű harisnyakötőgép a 19. századból", by Elkágyé, 2019, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Clarinet: "Grifftabelle für eine Zwei-Klappen-Klarinette, Abbildung aus Majers "Museum Musicum" von 1732", by Unknown authorUnknown author, 2024, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Clark electrode: "Clark Electrode", by Leland C. Clark, 1959, licensed under FAL, via Wikimedia Commons. View source. View in tree.
• Class-D amplifier: "Block diagram of a PWM switching amplifier.", by Rohitbd, 2006, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Claude air liquefaction: "Liquid nitrogen", by Cory Doctorow aka gruntzoki on Flickr, 2008, licensed under CC BY-SA 2.0, via Wikimedia Commons. View source. View in tree.
• Claus process: "Large sulfur pile at North Vancouver, B.C., Canada. This is brought by rail from the adjacent province of Alberta. This is a loading station for large bulk transport ships. For the Sulfur article. Image taken by User:Leonard G. June 13, 2005. Photographers note: this was a day of over 9/10 cloud cover, with small, bright patches of sunlight passing through the area. This was the most satisfactory result of a number of attempts to catch the sulfur piles in sun and other regions in cloud shadow. Camera: single lens 35mm reflex with 28-208mm zoom, ASA 200 color negative.", by Leonard G., 2005, licensed under CC SA 1.0, via Wikimedia Commons. View source. View in tree.
• Clay tokens: "이집트 고대 도시 수사에서 발견된 토큰", by Marie-Lan Nguyen, 2009, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Clinker boat building: "Nydam Boat Gottorp Slot", by Erik Christensen, 2014, licensed under CC BY 3.0, via Wikimedia Commons. View source. View in tree.
• Closed-core transformer: "First transformers (Déri-Bláthy-Zipernowsky, Budapest 1885.) Széchenyi István Memorial Exhibition in Nagycenk", by Zátonyi Sándor, (ifj.), 2004, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Clothing: "The Tarkhan Dress", by Nic McPhee, 2008, licensed under CC BY-SA 2.0, via Wikimedia Commons. View source. View in tree.
• Cloud chamber: "The only original cloud chamber used by C.T.R. Wilson to detect the traces of subatomic particles. According to Wilson, the material price for the experiment was only around 5 British pounds. The historic cloud chamber is located in the Cavendish Laboratory at Cambridge University.", by Rolf Kickuth, 2013, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Cloud computing: "Diagram showing overview of cloud computing, with typical types of applications supported by that computing model.", by Sam Johnston, 2009, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• CMOS: "CMOS inverter. Picture is not language dependant and is usable in all the wikis, whatever the language.", by Abaddon1337, 2012, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Coade stone: "South Bank Lion Originally a logo for a brewery, this lion stood outside a pub that was flattened in the Blitz before moving here to the south side of Westminster Bridge, at the request of the King. Made from a secret process called Coade stone, it is a casting rather than a carving. Kensington Gardens SW7 Tube: South Kensington", by Leonora Enking from West Sussex, England, 2011, licensed under CC BY-SA 2.0, via Wikimedia Commons. View source. View in tree.
• Coal gas and gas lighting: "Drawing the retorts at the Great Gas Works at Brick Lane", by Unknown authorUnknown author, 1821, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Coal power plant: "The world's first public steam-driven coal power station.", by From an article by Jack Harris, New Scientist (1982). The photo was taken between 1882-1886, whilst the Holborn Viaduct power station was running., 1882, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Coat of plates: "Detail of a mid-13th century german manuscript.", by Alexander of Bremen (d. 1271), 1249, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Cobalt: "Pure (99.9 %) cobalt chips, electrolytically refined, as well as a high purity (99.8 % = 2N8) 1 cm3 cobalt cube for comparison.", by Alchemist-hp (talk) (www.pse-mendelejew.de), 2010, licensed under FAL, via Wikimedia Commons. View source. View in tree.
• Cocaine: "Bottle for cocaine solution 2.jpg", by Science Museum Group Studio, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Cochineal dye: "Material dyed from cochineal", by ArbyBB, 2022, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Cochlear implant: "Cochlear Implant. See a full animation of this medical topic.", by BruceBlaus. When using this image in external sources it can be cited as: Blausen.com staff (2014). "Medical gallery of Blausen Medical 2014". WikiJournal of Medicine 1 (2). DOI:10.15347/wjm/2014.010. ISSN 2002-4436., 2013, licensed under CC BY 3.0, via Wikimedia Commons. View source. View in tree.
• Cockcroft–Walton generator: "1.2 megavolt Cockcroft-Walton particle accelerator (background) at the Clarendon Laboratory, Oxford University, UK in 1948. It consists of a 6 stage voltage multiplier stack with a large globe to store charge at the top. The black segments of each column contain capacitors to store the charge, while the diagonal "crossrungs" contain high voltage vacuum tube rectifiers called kenotrons, which only conduct current in one direction. An alternating voltage of several hundred kilovolts is applied between the bottom columns. The columns function as a charge pump, pumping electric charge up the columns until the top terminal is at a potential of 1.2 million volts. The voltage is applied to opposite ends of an evacuated accelerator tube (not shown) which accelerates charged subatomic particles traveling through it to high speeds. All the metal parts of the machine must be covered by smooth curved metal "corona rings" to prevent corona discharge, which can cause charge to leak into the air. The Cockcroft-Walton accelerator was invented by British physicists John Douglas Cockcroft and Ernest Thomas Sinton Walton in 1932.", by Unknown authorUnknown author, 1948, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Cocoa powder: "press cake of cocoa", by Chianti, 2016, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Codex: "Codex Gigas", by Kungl. biblioteket, 2005, licensed under Attribution, via Wikimedia Commons. View source. View in tree.
• Coffee: "A dallah a traditional Arab coffee pot with cups and coffee beans", by Canbel, 2017, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Coffee filter: "Melitta coffee filter holder of size 102 with (too large) paper coffee filter of size 1×4 (aka #4)", by Elke Wetzig (Elya), 2007, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Coffee percolator: "Perkulator", by Andreaze, 2008, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Cog: "Hansekogge „Roland von Bremen“ am Schlachte-Anleger in Bremen, Nachbau einer Hansekogge", by Eva K. / Eva K., 2006, licensed under CC BY-SA 2.5, via Wikimedia Commons. View source. View in tree.
• Coherer: "A coherer, a primitive radio wave detector used in the first radio receivers around the turn of the 20th century. This type was developed by Guglielmo Marconi in the late 1890s. It consists of a tube or capsule containing two electrodes spaced a small distance apart, with metal filings in the space between them. When a radio frequency signal is applied to the device, the initial high resistance of the filings reduces, allowing an electric current to flow through it.", by J. A. Davidson, specifically JA.Davidson., 2013, licensed under CC0, via Wikimedia Commons. View source. View in tree.
• Coins: "KINGS of Lydia. Uncertain King. Early 6th century BC. EL Third Stater - Trite (4.71 gm). Head of roaring lion right, sun with multiple rays on forehead / Double incuse punch. Weidauer 86; BMC Lydia pg. 2, 6; SNG Kayhan 1013.", licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Coke (fuel): "coke", by Stahlkocher, 2006, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Collodion: "Alfred Stieglitz, c.1894, collodion print by Frank S. Herrmann, Department of Image Collections, National Gallery of Art Library, Washington, DC", by Frank S. Herrmann, 1894, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Collodion wet-plate photography: "Photo of Gerona (or Girona), Spain, circa 1867. Photo by Jose Martinez Sanchez, associated with J. Laurent. The original glass negative is preserved in Madrid, in the Photo Library of the Institute of Cultural Heritage of Spain.", by CARLOS TEIXIDOR CADENAS, 2014, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Color motion picture film: "Object from the National Media Museum Collection. Edward Turner’s method for creating moving colour pictures was to record successive frames on black and white film through red, green and blue filters and to project these sets of three frames superimposed through similar filters. Images are projected through red, green and blue filters onto a screen at the rate of 16 pictures per second.", by National Media Museum from UK, 2008, licensed under No restrictions, via Wikimedia Commons. View source. View in tree.
• Color photography: "Tartan Ribbon, photograph taken by James Clerk Maxwell in 1861. Considered the first durable colour photographic image, and the very first made by the three-colour method Maxwell first suggested in 1855. Maxwell had the photographer Thomas Sutton photograph a tartan ribbon three times, each time with a different colour filter (red, green, or blue-violet) over the lens. The three photographs were developed, printed on glass, then projected onto a screen with three different projectors, each equipped with the same colour filter used to photograph it. When superimposed on the screen, the three images formed a full-colour image. Maxwell's three-colour approach underlies nearly all forms of colour photography, whether film-based, analogue video, or digital. The three photographic plates now reside in a small museum at 14 India Street, Edinburgh, the house where Maxwell was born.", by James Clerk Maxwell, 1861, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Color television: "This is a photograph of the first color television image displayed for the public in the UK, a demonstration made by famed Scottish television pioneer, John Logie Baird in 1941. The image was produced by a two-color system using dual projection CRTs combining their image onto a screen. The image shows famed adventurer Paddy Naismith, known as a race driver, air hostess and model of the 1930s and 40s.", by Journal of The Television Society, 1941, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Colt revolver: "Colt Paterson 5th Model", by Hmaag, 2016, licensed under CC0, via Wikimedia Commons. View source. View in tree.
• Combine harvester: "Old Style Sunshine Harvester found in Henty region of NSW Australia", by Virtual Steve, 2007, licensed under CC BY-SA 2.5, via Wikimedia Commons. View source. View in tree.
• Combined oral contraceptive pill: "Pilule contraceptive.jpg", licensed under CC BY-SA 2.0 fr, via Wikimedia Commons. View source. View in tree.
• Commercial telegraphy: "William Fothergill Cooke and Charles Wheatstone's electric telegraph ("needle telegraph") from 1837 now in the London Science Museum", by Geni, 2008, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Communications satellite: "An Atlas-B missile (s/n 10B) being prepared to launch the SCORE satellite from Cape Canaveral LC-11.", by U.S. Air Force, 1958, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Commutated rotary electric motor: "The first Jedlik motor", by http://www.jedliktarsasag.hu/, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Compact disc: "Flat view of a CD-R, with interference colours. Sorry about the dust fibres. Saved as JPG with IrfanView at 90% quality. Scanned by me with an HP ScanJet 4400c, and run through ACDSee's "auto-level" filter.", by derivative work: Dzucconi (talk) CD_autolev_crop.jpg: Ubern00b, 2008, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Compact fluorescent lamp: "Compact fluorescent light bulb", by http://en.wikipedia.org/wiki/User:PiccoloNamek, 2009, licensed under CC BY 3.0, via Wikimedia Commons. View source. View in tree.
• Compass: "Chinesischer Kompass; im Überseemuseum", by Bin im Garten, 2011, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Complete garment knitting machine: "Rundstrickmaschine Zungennadeln.jpg", licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Compound microscope: "Robert Hooke's microscope. From Scheme I. of his 1665 Micrographia. On permanent display in "The Evolution of the Microscope" exhibit at the National Museum of Health and Medicine, in Washington, DC.", by Robert Hooke, 1665, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Comptometer: "Front picture of a very early comptometer", by Ezrdr, 2009, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Compton scattering: "Light-matter interaction diagrams.", by Ponor, 2020, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Computer network: "SAGE control room.png", licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Computer program: "Diagram of an algorithm for the Analytical Engine for the computation of Bernoulli numbers, from Sketch of The Analytical Engine Invented by Charles Babbage by Luigi Menabrea with notes by Ada Lovelace", by Ada Lovelace, 1842, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Computer-assisted instruction system: "PLATO running a fractional distillation simulation", by Jason Scott, licensed under CC BY-SA 3.0 us, via Wikimedia Commons. View source. View in tree.
• Computer-generated imagery: "Theatrical poster for the film Vertigo. Restored by Adam Cuerden. Work done: Long fold (?) marks removed. Minor blobs fixed.", by Saul Bass / Adam Cuerden, 1958, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Concept of chemical element: "Table of contents to a 1789 copy of volumes 1 of "Traité élémentaire de Chimie, présenté dans un ordre nouveau, et d’après les découvertes modernes" by Antoine Lavoisier. Copy located in the Niels Bohr Library & Archives, American Institute of Physics, in College Park, Maryland.", by Lavoisier, Antoine-Laurent de, 1789, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Conching: "Hershey Conche in the early 1900s made by J.M. Lehmann in Dresden / Paris. This machine is on display as part of the Hershey Story Collection.", by Z22, 2014, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Concrete: "Bloczek betonowy.", by Ablazejo, 2014, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Condensed milk: "Advertisement for Borden's Eagle Brand Condensed Milk; from a guidebook published by the Alaska Commercial Company for people traveling to Alaska and the Yukon in the Klondike Gold Rush. (cropped; a printing defect in the original booklet resulted in the blurred appearance)", by Unknown illustrator, 1898, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Condenser microphone: "Oktava MK-319 condenser microphone (internal view)", by Gregory F. Maxwell <gmaxwell@gmail.com> PGP:0xB0413BFA, 2005, licensed under GFDL 1.2, via Wikimedia Commons. View source. View in tree.
• Conex box: "US Army conex box", by Wikideas1 (talk) (Uploads), 2017, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Congreve rocket: "Congreve rockets.gif", licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Construction mortar: "Roman mortar, found beneath the Norman (?) near School room, Chethams Hospital, Sept 1900. Chetham's Library, Manchester, United Kingdom", by Photograph by Mike Peel (www.mikepeel.net)., 2015, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Contact lens: "Contactlenzen Confortissimo.JPG", licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Contact process: "Scheme of contact process (process which is widely used to make sulfuric acid). Text in picture is in Finnish.", by QWerk, 2009, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Container ship: "Netwerk dag van Piet Sinke van Maasmond Maritiem aan boord van de ELBE , vanuit Maassluis via de Rozenburgsluis naar de Maasvlakte 2", by kees torn, 2019, licensed under CC BY-SA 2.0, via Wikimedia Commons. View source. View in tree.
• Continuous track snow vehicle: "William Lashly standing by a Wolseley motor sleigh during the British Antarctic Expedition of 1911-1913, November 1911 Photographer: Herbert Ponting Reference Number: PA1-f-067-086-4 Silver gelatin print Photographic Archive, Alexander Turnbull Library Find out more about this image from the Alexander Turnbull Library.", by Herbert Ponting, 1911, licensed under No restrictions, via Wikimedia Commons. View source. View in tree.
• Continuous track tractor: "The Holt 75 model gasoline-powered half-tracked ("caterpillar") tractor, circa 1914, used early in World War I as an artillery tractor. Later models were produced without the front "tiller wheel."", by Unknown authorUnknown author, 1914, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Continuous track vehicle: "Ed. Lacroix Ltée Tractor No 6. French Canadian Edouard Lacroix's Madawaska Company was a lumber company operating in northern Maine were it built the small town of Churchill Depot to supply his lumber camps and where his repair shop was; the shop could accommodate 12 gazoline Lombard Log Haulers (the were numbered 1 to 26). This number 6 was renovated and is shown at the Maine State Museum of Augusta.", by Edouard Lacroix, 1925, licensed under CC0, via Wikimedia Commons. View source. View in tree.
• Continuously recording camera: "The first successful camera for making continuous recordings of scientific instruments, built by Francis Ronalds in 1845. This example is an electrograph measuring atmospheric electricity", by Tissandier, G., 1873, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Control of fire: "This is an image of "African people at work" from", by Tanja Lage, 2017, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Controlled-access highway: "Varese-Como junction of the Laghi motorway in Peschiera Borromeo (Milan), Italy in the 1950s.", by Unknown (from Mondadori Portfolio collection), 1956, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Convection oven: "Industrial convection oven used in the aircraft manufacturing industry", by Coosbane, 2004, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Convolutional neural network: "Illustration for CNN", by Daniel Voigt Godoy, 2021, licensed under CC BY 4.0, via Wikimedia Commons. View source. View in tree.
• Copernican heliocentrism: "Image of heliocentric model from Nicolaus Copernicus' "De revolutionibus orbium coelestium".", by Copernican_heliocentrism_diagram.jpg: Own work from Copernicus 1543 derivative work: Professor marginalia (talk), 2010, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Copper: "Macro of native copper about 1 ½ inches (4 cm) in size.", by Native_Copper_Macro_Digon3.jpg: “Jonathan Zander (Digon3)" derivative work: Materialscientist (talk), 2009, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Copper pipes: "Lead plug belonging to the copper basins connected to the drainage system. Taken from Ludwig Borchardt's Das Grabdenkmal des Königs Sahur-Re (1910).", by Ludwig Borchardt, 1910, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Copper smelting: "Minoan copper ingot from Zakros, Crete.", by Chris 73, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Copying lathe: "Harpers Ferry Armory gunsmith shop had machines for production of the lock, the stock and the barrel. The machines are from the 1850s and are all powered by water. The power is transmitted to the machine by a set of pulleys and leather belts. This machine is a Duplicating or Blanchard lathe used to create stock identical to a pattern.", by Jarek Tuszyński, 2015, licensed under CC BY 4.0, via Wikimedia Commons. View source. View in tree.
• Corbel arch: "Ugarit Palace Entrance", by Disdero (talk · contribs), 2005, licensed under CC BY 3.0, via Wikimedia Commons. View source. View in tree.
• Corbel arch bridge: "Surviving example of Mycenaean bridge construction in Argolis, Peloponnesos", by Flausa123, 2012, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Corliss steam engine: "Corliss engine, showing valvegear (New Catechism of the Steam Engine, 1904).jpg", by Andy Dingley (scanner), licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Corn tortilla: "Detail of the Codex Mendoza's folio 60r", by Aztec painter : Francisco Gualpuyogualcal?, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Corneal contact lens: "Contactlenzen Confortissimo.JPG", licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Cornu helicopter: "In 1907, the French inventor Paul Cornu made a helicopter that used two 20-foot (6-meter) counter-rotating rotors driven by a 24-hp (18-kW) Antoinette engine. It lifted its inventor to about five feet (1.5 meters) and remained aloft one minute.", by Unknown authorUnknown author, 1907, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Corridor: "A hallway at the Luhrs Tower in Phoenix, Arizona", by Visitor7, 2013, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Corrugated galvanised iron: "Mount Lawley rooftops (corrugated galvanised iron), Fourth Avenue, Mount Lawley, Western Australia.", by Photograph by Greg O'Beirne, 2002, licensed under CC BY 2.5, via Wikimedia Commons. View source. View in tree.
• Cotton (New World): "Tree cotton photographed at Huntington Gardens (Los Angeles) in October.", by Raffi Kojian, 2009, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Cotton (Old World): "CottonPlant.JPG", licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Cotton gin: "Eli Whitney's Patent for the Cotton gin, March 14, 1794; Records of the Patent and Trademark Office; Record Group 241, National Archives.", by Eli Whitney, 1794, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Counterweight trebuchet: "1187 مقذاف مرضي بن علي الطرسوسي", by مرضي بن علي الطرسوسي, 2020, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Crab claw sail: "Pirogue des naturels de l'île Obalahou. Atlas pittoresque, planche 96", by Louis Le Breton, 1846, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Crane: "Model of a Roman winch crane in the American Center of Oriental Research in Amman, Jordan.", by Michael Gunther, 2014, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Crank: "Ancient Roman iron crank from Augusta Raurica, Switzerland. The 82.5 cm long piece with a 15 cm long handle is of yet unknown purpose and dates to no later than ca. 250 AD.[1] Current location: Museum Augusta Raurica, Inv.-No. 1962.7849", by Beat Rütti, Susanne Schenker, 2009, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Crank-slider mechanism: "Scheme of the Roman Hierapolis stone sawmill. The 3rd century AD watermill is the first known machine to incorporate a crankshaft and connecting rod.", by 論, 2009, licensed under CC BY 3.0, via Wikimedia Commons. View source. View in tree.
• Credit card: "Credit cards", by Lotus Head from Johannesburg, Gauteng, South Africa, 2005, licensed under CC BY-SA 2.5, via Wikimedia Commons. View source. View in tree.
• CRISPR gene editing: "CRISPR Cas9 system", by marius walter, 2017, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Crochet: "The illustration is accompanied by crochet instructions which, at the time of uploading, are the earliest noted in the present-day literature.", by A. B. Van Meerten, 1824, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Crookes radiometer: "Crookes radiometer (or light mill), consists of an airtight glass bulb, containing a partial vacuum. Inside are a set of vanes which are mounted on a spindle. The vanes rotate when exposed to light, with faster rotation for more intense light, providing a quantitative measurement of electromagnetic radiation intensity.This radiometer has been enhanced to associate an electrical measuring device", by Lamiot, 2016, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Crookes tube: "Cathode rays in magnetic field. (Crookes tube; U = 0; B = 0)", by Zátonyi Sándor, (ifj.), 2002, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Crossbow (China): "A Chinese crossbow with a buttplate from either the late Warring States Period (3rd century BC) or the early Han Dynasty (202 BC – 220 AD); made of bronze and inlaid with silver.", by Gary Lee Todd, 2008, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Crossbow (Greece): "Reconstruction of a Gastraphetes, an ancient Greek crossbow, in the Saalburgmuseum at Bad Homburg v. d. Höhe, Hesse, Germany.", by Hartmann Linge, 2009, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Crucible steel: "Watered pattern on iranian sword blade.", by Rahil Alipour Ata Abadi, 2010, licensed under GFDL, via Wikimedia Commons. View source. View in tree.
• Cruise control: "1967 Ambassador 990 series, four-door sedan made by American Motors Corporation (AMC). This is a luxurious full-size, six adult passenger automobile with trunk space for all their luggage. This car is finished in yellow with the interior featuring individually adjustable (50-50) reclining front seats and all done in the standard black brocade upholstery. This car is powered by AMC's new for 1967 engine family, the standard 290 CID (4.75 L) V8 and automatic transmission. It also has factory "Weather Eye" air conditioning system and AMC's "cruise-command" speed control. Picture was taken in Miami, Florida.", by CZmarlin — Christopher Ziemnowicz, releases all rights but a photo credit would be appreciated if this image is used anywhere other than Wikipedia. Please leave a note at Wikipedia here. Thank you!, 2015, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Cruise missile: "For documentary purposes the German Federal Archive often retained the original image captions, which may be erroneous, biased, obsolete or politically extreme. V1 vor dem Start Aus guter Deckung wird "V1" an die Abschußstelle gerollt. Der Start erfolgt durch eine Pressluftanlage. Mit Hilfe eines Fernlenkverfahrens trifft die "V1" das befohlene Ziel. Die gleichbleibend hohe Geschwindigkeit, die von keinem Feindjäger erreicht wird, erhält "V1" von einem Raketenantrieb. Diese erste deutsche Vergeltungswaffe ist eine hervorragende Schöpfung unserer Luftrüstung. Foto: PK-Lysiak/Transocean-Europapress", by Lysiak, 1944, licensed under CC BY-SA 3.0 de, via Wikimedia Commons. View source. View in tree.
• Cryptocurrency: "Logo of Bitcoin", by Grayliptrot, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Crystal detector: "A galena cat's-whisker detector, an early radio wave detector used in crystal radio receivers from about 1905 to the 1940s. The fine metal wire attached to the adjustable arm touches the face of a natural semiconducting crystal of galena (lead sulfide) in the capsule at right. The contact forms a PN junction making a crude semiconductor diode. In a crystal radio its function is to rectify the alternating current radio signal, extracting the audio (sound) signal from the radio frequency carrier wave. Only certain sites on the crystal surface function as rectifying junctions, so the device had to be adjusted before each use by dragging the wire across the crystal to find a "sweet spot".", by JA.Davidson, licensed under Copyrighted free use, via Wikimedia Commons. View source. View in tree.
• Crystal oscillator: "Four precision 100 kHz quartz crystal oscillators maintained by the US Bureau of Standards (now the National Institute of Standards and Technology that served as the frequency standard for the United States in 1929. Built by Bell Telephone Laboratories, where the quartz crystal oscillator was invented in 1923, they achieved a frequency stability of 10-7. The oscillators are enclosed in temperature controlled ovens kept at a precisely constant temperature to prevent thermal expansion and contraction of the quartz resonator, which would cause changes in frequency. The large crystal resonators are mounted under the glass domes visible on top of the units.", by Unknown authorUnknown author, 1929, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Crystal radio: "Swedish crystal radio made by Radiola with earphones. The device at top is the radio's cat's whisker detector.", by Holger.Ellgaard, 2008, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Crystallized sugar: "Raw (unrefined, unbleached) sugar, bought at the grocery store.", by Editor at Large, 2007, licensed under CC BY-SA 2.5, via Wikimedia Commons. View source. View in tree.
• CT scan: "Modern CT scanner located at the Lochotín University Hospital in Pilsen, Czech Republic.", by Tomáš Vendiš, 2022, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Cultured meat: "A dish of spring vegetable pasta with four strips of GOOD Meat Cultivated Chicken, a lab-grown chicken product by Eat Just. Taken at Huber's Butchery in Singapore, at time of writing the only restaurant in the world offering cultivated meat to the public. This image is also used on my own blog: https://driftingclouds.net/2023/06/15/i-paid-22-to-eat-the-lab-grown-chicken-nugget-of-an-unlikely-future/", by Jpatokal, 2023, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Cupronickel: "Euthydemos II cupro-nickel. Circa 185-180 BC. Cupro-Nickel Double Unit (23mm, 7.83 g, 12h). Laureate head of Apollo right / Tripod; monogram to inner left.", by CNG Coins, 2018, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Curta calculator: "Curta mechanical computer", by Rama, 2008, licensed under CC BY-SA 2.0 fr, via Wikimedia Commons. View source. View in tree.
• Cyclostyle: "Hendrik Conscience Heritage Library in Antwerp", by Saeidpourbabak, 2016, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Cyclotron: "Cyclotron with glowing beam.jpg", licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Cylinder seal: "Cylinder seal and sealing impression: the king-priest and his acolyte feeding the sacred herd. White limestone, Uruk period, ca. 3200 BC.", licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Czochralski method: "A silicon crystal being grown by the Czochralski process at the Raytheon Corp. semiconductor plant in Newton, Massachusetts, USA, in 1956 for use in the first silicon transistors. The transistor was invented in 1946, and the Czochralski process was first used to grow silicon crystals to make the first silicon transistors at Bell Labs in 1953, so this is one of the earliest silicon crystal production plants. The induction heating coil visible around the crucible carries a radio frequency current, and the heat induced melts the pure silicon in the crucible at a temperature of 2650°F. A seed crystal of solid silicon is attached to the rod and is lowered into the tube to touch the surface of the melted silicon. By carefully controlling the temperature distribution using the induction heater, the melted silicon is induced to crystallize on the seed, adding to the crystal. The seed is slowly pulled up from the melt, and the silicon freezes onto the end, creating a solid rod of monocrystal silicon. Here the process has just begun, and the tapered end of the crystal is visible just below the rod. In this early device the silicon crystal was only 1 inch wide. The woman is measuring the temperature of the melt with an optical pyrometer. This device has a filament attached to a calibrated current source inside the viewing tube, which appears silhouetted in front of the hot silicon. The technician turns up the current until the luminous filament just disappears against the background of the glowing silicon. This means the filament and the silicon are at the same temperature. The current knob (bottom) is calibrated in temperature, so she can read the temperature of the silicon off the knob. Alterations to image: Cropped out portions of magazine cover containing text, straightened, removed obvious dirt and damage.", by George E. Meyers, 1956, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Daguerreotype: "L’Atelier de l'artiste : un daguerréotype de 1837, réalisé par l’inventeur de ce procédé photographique, Louis Jacques Mandé Daguerre (1787-1851).", by Louis Daguerre, 1837, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Dandy horse: "Karl von Drais riding his draisine", by photo Lesseps artist unknown, 1819, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Daniell cell: "Early batteries. Daniell cell batteries, 1836, by John Frederic Daniell (England). Exhibit in National Museum of American History, Washington, DC, USA.", by Cruickshank trough battery, 1801, and Daniell cell batteries, 1836.jpg: Daderot derivative work: Wdwd (talk), 2011, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Data Encryption Standard: "Flow diagram for DES processing", by Hellisp, 2014, licensed under CC0, via Wikimedia Commons. View source. View in tree.
• Davy lamp: "Davy's first safety lantern, 1815, and early wire gauge safety lamp, Science Museum, South Kensington, Acme Newspictures, c. December 1929, from the Digital Commonwealth - 1 22 10 001309 0004 A. Note: this original caption appears incorrect; the Davy lamp is at the left, and it is unclear what lamp is at the right.", by Acme Newspictures (New York City), 1929, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• de Laval nozzle: "Продольное сечение реактивного двигателя РД-107 (Государственный музей истории космонавтики имени К. Э. Циолковского)", by Albina-belenkaya, 2014, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• De Rivaz engine: "Uploaded from Eckermann, Erik (2001). World history of the automobile. SAE. pp. 18 - 19. ISBN 076800800X. https://books.google.com/books?id=yLZeQwqNmdgC&pg=PA18&dq=fran%C3%A7ois+isaac+de+rivaz+engine&hl=en&ei=jVG9TdG2Hsy38gPv1eC2BQ&sa=X&oi=book_result&ct=result&resnum=5&ved=0CD4Q6AEwBA#v=onepage&q&f=false.", by François Isaac de Rivaz 1752 – 1828), 1804, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Deep ultraviolet lithography: "EUVL tool, that deposits virtually defect-free, ultra-thin films on integrated circuits.", by Lawrence Livermore National Laboratory, 1998, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Defibrillator: "Claude S. Beck's defibrillator prototype from 1947. Collection of the National Museum of American History.", by Brigade Piron, 2023, licensed under CC BY 3.0, via Wikimedia Commons. View source. View in tree.
• Dental braces: "Diagramme de Pierre Fauchard sur la restauration des dents.jpg", licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Dental filling: "Inlay made of IPS e.max Press", by AmirAttallah, 2018, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Dentures: "Etruscans, people living in Etruria (Umbria and Tuscany, Italy), were the first to make dentures and false teeth, from 700 BCE onwards. Teeth from another person or an animal, such as an ox, were inserted into a band of gold with a metal pin and fitted on to the remaining teeth. Imagine eating with another person’s teeth! Only wealthy people could afford this treatment. There were no specialist dentists so dentistry was one of the duties of a physician. This is a copy of an original denture with two teeth, which was found in a tomb in Etruria, Italy. maker: Unknown maker Place made: Europe Wellcome Images Keywords: denture; prostheses; dental bridge; Dentistry", licensed under CC BY 4.0, via Wikimedia Commons. View source. View in tree.
• Destroyer: "Spanish Navy torpedo gunboat Destructor, designed and built in the UK by Thomson and delivered to the Spanish Navy in 1887", by Unknown authorUnknown author, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Detent escapement: "Le_Roy_escapement_mechanism", by Ferdinand Berthoud, 1802, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Dhow: "This is an image of "African people at work" from", by Africraigs, 2010, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Diamond anvil cell: "First diamond anvil cell (1958) on display at NIST Gaithersburg Museum", by Gasper J. Piermarini, 2001, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Dichroic glass: "The most magnificent of all ancient #Roman ‘cage cups’ is the 4th c. CE Lycurgus Cup, made of dichroic glass. In normal light, the glass appears milky green, when backlit, it glows a ruby red. The effect was achieved by adding silver and gold nanoparticles to the glass.", by Chappsnet, 2023, licensed under CC BY 4.0, via Wikimedia Commons. View source. View in tree.
• Dictionary: "Wörterbuchstapel Langenscheidt", by Langenscheidt, 2014, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Didymium: "Samarskite-(Y) (Size: 4.6 x 4.6 x 3.0 cm) Locality: Setesdal, Aust-Agder, Norway A large, 3-dimensional, robust crystal of this very complex rare earth element containing species with niobium and tantalum in addition to uranium and other oddities mixed in. This is an older specimen, undoubtedly. Al obtained it in 1967 and it is labeled "Setesdal" although we cannot find a reference to this locality. It may instead be from a nearby and known location, as Setesdal seems to be a valley district and not a specific mine name. However, Bernard and Hyrsl’s “Minerals and their Localities” does include a listing for Setesdal. Ex. Al Ordway Collection.", by Robert M. Lavinsky, 2010, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Diesel engine: "Diesel engine built by Langen & Wolf in 1898. This engine was built using the original Diesel design from 1897 and is possibly one of the oldest Diesel engines in Austria. Rated power is 14.7 kW.", by Johannes Maximilian, 2018, licensed under GFDL 1.2, via Wikimedia Commons. View source. View in tree.
• Diesel locomotive: "Dieselelektrischer Triebwagen ABm 2/5 9 (ex. BCm 2/5 9) des Régional du Val-de-Travers (RVT) mit Baujahr 1914, ausgestellt im Verkehrshaus der Schweiz in Luzern.", by Benutzer commons.limousin, 2010, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Diesel power shovel: "Canada's biggest power shovel loading an ore train with asbestos at the Jeffrey Mine, Johns-Manville Co., Asbestos, Quebec, June 1944.", by Harry Rowed, 1944, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Difference engine: "A photo of the Difference Engine constructed by the Science Museum based on the plans for Charles Babbage's Difference Engine No. 2", by User:geni, 2008, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Differential gear: "Differential (Manual of Driving and Maintenance).jpg", by Andy Dingley (scanner), 1937, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Diffusion pump: "Early mercury diffusion pump developed by Irving Langmuir at General Electric in 1916. The diffusion pump is the vertical chamber in the foreground, the machine in the background is the "backing pump" required to establish the initial low vacuum. The mercury diffusion pump was invented by German researcher W. Gaede in 1913. Langmuir's innovation was a nozzle that directed the mercury vapor away from the inlet, allowing the inlet to be made larger, greatly increasing the pumping speed. He received a patent on his "mushroom cap" nozzle in 1921. The Langmuir pump, which achieved pressures down to 10-10 atmosphere, enabled the production of the first "hard vacuum" thermionic valves (vacuum tubes) which dominated radio and electronics technology for 50 years. It also was important for making incandescent light bulbs. Alterations to image: removed unrelated text from accompanying article from white area in upper right corner of image.", by E. E. Free, 1922, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Digging stick: "Nuba person farming on the hilltop, Nuba Mountains — southern Sudan.", 2001, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Digital audio player: "Archos mp3/video-speler", by Michiel1972 at Dutch Wikipedia, 2004, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Digital camera: "Cromemco Cyclops: First all-digital camera with solid-state area image sensor. Original design appeared in the February 1975 issue of Popular Electronics", by [[User:jacobtarango, 2013, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Digital cellular network: "Structure of a GSM network (key elements). Based on 3GPP TS 23.002", by Tsaitgaist, 2009, licensed under GPLv3, via Wikimedia Commons. View source. View in tree.
• Digital currency: "Taxonomy of money, based on "Central bank cryptocurrencies" by Morten Linnemann Bech and Rodney Garratt.", by Stanjourdan, 2017, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Digital printing: "Large format digital printer", by Caroline Culler (User:Wgreaves), 2015, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Digital programmable computer: "Replica of the Zuse Z3 in the Deutsches Museum in Munich, Germany", by Venusianer at German Wikipedia, 2006, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Digital video recorder: "Front view of a TiVo EDGE DVR For Cable", by TiVo Corp., 2019, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Dioptra: "Dioptra", by H. Schöne. - Leipzig: B. G. Teubner, 1903 Original uploader was Klingsor at German Wikipedia, 1903, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Directed evolution: "An example of directed evolution with comparison to natural evolution. The inner cycle indicates the 3 stages of the directed evolution cycle with the natural process being mimicked in brackets. The outer circle demonstrates steps a typical experiment. The red symbols indicate functional variants, the pale symbols indicate variants with reduced function.", by Thomas Shafee, 2014, licensed under CC BY 4.0, via Wikimedia Commons. View source. View in tree.
• Dirigible: "Giffard1852.jpg", licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Discovery of Neptune: "This is a rare illustration of Neptune in pre-Voyager times. It is based on the observation by Thomas Jefferson Sèe in 1919.", by T.J. Sée, 1919, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Discovery of Uranus: "Uranus on 1986-01-23, taken by NASA's Voyager 2 probe. This color image was composed of three frames, orange, green, and blue, taken by Voyager 2's imaging system. This color image has been calibrated to best represent Uranus's true color and appearance. Based on: Irwin, Patrick G J (2023-12-23). "Modelling the seasonal cycle of Uranus’s colour and magnitude, and comparison with Neptune". Monthly Notices of the Royal Astronomical Society 527 (4): 11521–11538. DOI:10.1093/mnras/stad3761. ISSN 0035-8711.", by Ardenau4, 2024, licensed under CC0, via Wikimedia Commons. View source. View in tree.
• Discrete cosine transform: "This image shows the effect of applying eight different filters on a test image by multiplying the spectra obtained with discrete cosine transform (DCT). Common effect such as low-pass and high-pass can be seen. I created the image completely myself, using my own photo and Aileron font (CC0, by dot colon) and I release it under CC0. I used GIMP and GNU Octave. The Octave command used to filter the image is (consider CC0 as well): pkg load signal; for i = 1:24, img = uint8(idct2(dct2(double(rgb2gray(imread("~/Documents/fft dct examples/test.png")))) .* rgb2gray(double(imread(strcat("~/Documents/fft dct examples/filter",num2str(i),".png")))))); imwrite(img,strcat("~/Documents/fft dct examples/result",num2str(i),".png")); end The spectrum image is displayed directly without any smart mapping with: imshow(uint8(dct2(rgb2gray(imread("~/Documents/fft dct examples/test.png"))))) Therefore the values are cropped and the spectrum image loses some information about the original image. It is there only to give an idea about what the spectrum looks like.", by Drummyfish, 2019, licensed under CC0, via Wikimedia Commons. View source. View in tree.
• Dissolving views: "Magic lantern or slide projector", by Unknown authorUnknown author, 1886, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Distillation: "Byzantine Greek manuscript's illustration of Zosimos' distillation equipment", by Unknown Byzantine Greek illustrator, reproduced by Marcelin Berthelot in his 1887 text, Collection des anciens alchimistes grecs, 2015, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Divinatory compass: "Model Si Nan of Han Dynasty.jpg", licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Diving bell: "Alexander explores the sea in a submarine; detail of a miniature from BL Royal MS 15 E vi, f. 20v (the "Talbot Shrewsbury Book"). Held and digitised by the British Library.", by The Talbot Master, 1444, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Diving helmet: "Replica of the first diving helmet, created by brothers John and Charles Deane in 1832, on display at the History of Diving Museum.", by Divingenthusiast2005, 2022, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Diving machine: "Replica of the John Lethbridge barrel (1715), intermediate between diving bell and standard diving dress. Cité de la Mer, a maritime museum in Cherbourg, France.", by Ji-Elle, 2008, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Diving regulator: "Dykeri, fig 6, Nordisk familjebok.png", licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• DNA as the carrier of information: "DNA precipitated in water", by Bbkkk, 2008, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• DNA ligase: "DNA damage, due to environmental factors and normal metabolic processes inside the cell, occurs at a rate of 1,000 to 1,000,000 molecular lesions per cell per day. A special enzyme, DNA ligase (shown here in color), encircles the double helix to repair a broken strand of DNA. DNA ligase is responsible for repairing the millions of DNA breaks generated during the normal course of a cell's life. Without molecules that can mend such breaks, cells can malfunction, die, or become cancerous. DNA ligases catalyse the crucial step of joining breaks in duplex DNA during DNA repair, replication and recombination, and require either Adenosine triphosphate (ATP) or Nicotinamide adenine dinucleotide (NAD+) as a cofactor. Shown here is DNA ligase I repairing chromosomal damage. The three visable protein structures are: The DNA binding domain (DBD) which is bound to the DNA minor groove both upstream and downstream of the damaged area. The OB-fold domain (OBD) unwinds the DNA slightly over a span of six base pairs and is generally involved in nucleic acid binding. The Adenylation domain (AdD) contains enzymatically active residues that join the broken nucleotides together by catalyzing the formation of a phosphodiester bond between a phosphate and hydroxyl group. It is likely that all mammalian DNA ligases (Ligases I, III, and IV) have a similar ring-shaped architecture and are able to recognize DNA in a similar manner. (See:Nature Article 2004, PDF)", by Tom Ellenberger, Washington University School of Medicine in St. Louis., 2006, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• DNA polymerase: "structure of Homo sapiens DNA polymerase beta, pdb file 7ICG. A bound DNA is also indicated", by Yikrazuul, 2009, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• DNA profiling: "VNTR allelic length variation among 6 individuals", by PaleWhaleGail, uploaded to Wikimedia by Charvosi, 2008, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• DNA sequencer: "A row of DNA sequencing machines on SteelSentry tables (3730xl DNA Analyzer machines from Applied Biosystems).", by Flickr user jurvetson, 2005, licensed under CC BY 2.0, via Wikimedia Commons. View source. View in tree.
• DNA sequencing: "The Sanger (chain-termination) method for DNA sequencing. (1) A primer is annealed to a sequence, (2) Reagents are added to the primer and template, including: DNA polymerase, dNTPs, and a small amount of all four dideoxynucleotides (ddNTPs) labeled with fluorophores. During primer elongation, the random insertion of a ddNTP instead of a dNTP terminates synthesis of the chain because DNA polymerase cannot react with the missing hydroxyl. This produces all possible lengths of chains. (3) The products are separated on a single lane capillary gel, where the resulting bands are read by a imaging system. (4) This produces several hundred thousand nucleotides a day, data which require storage and subsequent computational analysis", by Estevezj, 2012, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Döbereiner's lamp: "Unterteil: zylindrisches Glasgefäß mit nach inne gewölbtem Boden. Durch ein Metallstück an dem sich der Zündmechanismus befindet mit dem oberen Teil verbunden. Oberteil: kugelförmiges Glasgefäß, an der Oberseite offen, nach unten in ein Glasrohr mündend, welches in den Unterteil hinein reicht. Auf dem Oberteil die Gravur: "Hiettel / in / Tetschen." Die Schrift ist von einem Floralmuster umfasst, welches in Form von zwei, unter der Schrift mit einer Schleife gebundenen Planzenranken erscheint. Döbereinsches Feuerzeug = Die Reaktion von verdünnter Schwefelsäuere mit Zink erzeugt Wasserstoff, der, katalysiert über "Platinschwamm" , als Knallgasreaktion mit Sauerstoff zu Wasser verbrennt. Eine sinnvolle Konstruktion erlaubt die kontrollierte Verwendung dieser Reaktion: Das Zink ist räumlich von der Schwefelsäure getrennt, so dass nur bei Bedarf Wasserstoff erzeugt wird, geregelt durch ein Ventil vor dem Platinschwamm und damit vor der Knallgasreaktion. So wird die Funktion als Feuerzeug ermöglicht. Sie wird nach 1880 überflüssig durch Zündholz und Feuerzeug, da hierbei die aufwändige Befüllung mit Schwefelsäure entfällt. "Es eine höchst angenehme Empfindung sei, wenn wir eine bedeutende Naturkraft technisch also bald zu irgend einem nützlichen Gebrauch eingeleitet sehen: und so bin ich in dem Falle, mich Ew. Wohlgeboren immer dankbar zu erinnern, da Ihr so glücklich erfundenes Feuerzeug mir täglich zur Hand steht." Goethe 1826.", by unbekannt, Hersteller/in, 1825, licensed under CC BY 3.0 de, via Wikimedia Commons. View source. View in tree.
• Dock: "Dock for cruise ships in St Maarten in the Caribbean.", by John Workman, 2015, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Dog sled: "Carrying the mail and the Weekly Klondike Nugget, this service covered all the creeks adjacent to Dawson. The service was established by Jean (or Gene) Allen in 1898 .Klondike Gold Rush. Subjects (LCTGM): Sled dogs--Yukon--Dawson; Letter carriers--Yukon--Dawson; Newspaper carriers--Yukon--Dawson Subjects (LCSH): Nugget Express (Yukon)", by Asahel Curtis, 1898, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Dolby noise-reduction system: "Dolby 361 A-type noise reduction module. Picture created by PJ October 18 2011 using the Canon EOS 550D camera with a Tamron 28-75 mm f/2.8 lens.", by PJ, 2011, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Domain Name System: "Domain name space.svg", licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Domestic refrigerator: "DOMELRE refrigerator c. 1914", by Unknown authorUnknown author, 1914, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Domestication of barley: "Barley (Hordeum vulgare) - United States National Arboretum", by Cliff from Arlington, Virginia, USA, 2009, licensed under CC BY 2.0, via Wikimedia Commons. View source. View in tree.
• Domestication of bees: "Detail of a Bee Hieroglyph from the tomb complex of Senusret I, from his "Sedge and Bee" title-("Nesu-Bity").Also shown: Each T-(semi-circle) hieroglyph, and the partial of the Sedge hieroglyph.", by Keith Schengili-Roberts, 2007, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Domestication of cacao trees: "Page 1 du Codex Fejéváry-Mayer. Les 4 points cardinaux aztèques et les 4 signes "porteurs d’années". Au sud, le cacaotier. Foundation for the Advancement of Mesoamercan Studies, Inc. (FAMSI).", by Chaccard. Cropped by User:Andrew Dalby, 2013, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Domestication of cattle: "The bull (unicorn) in the bas-relief on the Ishtar Gate at the Pergamon Museum in Berlin.", by Josep Renalias, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Domestication of chickens: "Etruscan; Askos in the form of a cock; Vases", licensed under CC0, via Wikimedia Commons. View source. View in tree.
• Domestication of citrus fruit: "Chinese fan painting from the Song dynasty inspired by For Liu Jingwen (贈劉景文), a poem written by Su Shi. You must remember, the best scenery of the year, Is exactly now, when oranges turn yellow and tangerines green.", by Zhao Lingrang, 1070, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Domestication of coconuts: "Coconut palm. A habitus image of a tree; 1 fruit in the longitudinal cut; 2 stone core after removal of the middle and outer fruit peel; 3 the same cross cuts; 4 endosperm after removal of the stone peel (Koprah); 5 a piece of the endosperm with the embryo.", by Franz Eugen Köhler, Köhler's Medizinal-Pflanzen, 1897, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Domestication of cucumbers: "Cucumber fruit developing on plants possessing multiple lateral branching, which is atypical of commercial cucumbers. This type of branching is important because increasing branch number increases yield potential.", by Stephen Ausmus, USDA ARS, 2007, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Domestication of flax: "Köhler's Medizinal-Pflanzen in naturgetreuen Abbildungen mit kurz erläuterndem Texte : Atlas zur Pharmacopoea germanica, austriaca, belgica, danica, helvetica, hungarica, rossica, suecica, Neerlandica, British pharmacopoeia, zum Codex medicamentarius, sowie zur Pharmacopoeia of the United States of America /", by Brandt, Wilhelm; Gürke, M.; Köhler, F. E.; Pabst, G.; Schellenberg, G.; Vogtherr, Max., 1887, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Domestication of goats: "Glazed brick depicting a wild goat, from Nimrud, Iraq, 9th-7th century BCE. Iraq Museum, Baghdad, Iraq.", by Osama Shukir Muhammed Amin FRCP(Glasg), 2019, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Domestication of llamas and alpacas: "Llama, Moche", by Lombards Museum, licensed under CC BY 3.0, via Wikimedia Commons. View source. View in tree.
• Domestication of maize: "Image of seeding, tilling, and harvesting maize from the Digital Edition of the Florentine Codex created by Gary Francisco Keller. Images are taken from Fray Bernadino de Sahagún, The Florentine Codex. Complete digital facsimile edition on 16 DVDs. Tempe, Arizona: Bilingual Press, 2008. Reproduced with permission from Arizona State University Hispanic Research Center.", by Gary Francisco Keller, artwork created under supervision of Bernardino de Sahagún between 1540 and 1585., CC BY 3.0, via Wikimedia Commons. View source. View in tree.
• Domestication of pigeons: "Cassiano dal Pozzo water color copy of section 17 of the Nile Mosaic of Praeneste, made around 1627, probably by Vincenzo Manenti.", by Unknown authorUnknown author, possibly Vincenzo Manenti, 1627, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Domestication of pigs (China): "Art collection at the Capital Museum in Beijing", by gongfu_king, 2008, licensed under CC BY-SA 2.0, via Wikimedia Commons. View source. View in tree.
• Domestication of pigs (Near East): "Two men sacrificing a pig on an ancient Greek red-figure pot.", by DaphneBreemen, 2015, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Domestication of rice: "Reis. A blühendes Exemplar der Pflanze (var. melanoceras Alef.), unterer Teil. B Blütenrispe. C Fruchtrispe der var. italica Körnicke. D Fruchtzweig der var. Sundanensis Körnicke. 1 ein Ährchen von A; 2 dasselbe im Längsschnitt; 3 Staubblätter; 4 Ährchen stärker vergrössert nach Entfernung der unteren (grösseren) Spelze und eines Perigonblattes; 5 Endosperm mit Keimling von C; 6 Scheinfrucht von C im Längsschnitt; 7 Frucht von D; 8 dieselbe im Querschnitt. A, B, C, D etwas verkleinert; 1 bis 7 vergrössert.", by Franz Eugen Köhler, Köhler's Medizinal-Pflanzen, 1897, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Domestication of sheep: "Apulian red-figure ram-head rhyton of the Perrone-Phrixos Group: Nereide rides on a dolphin, to the right Skylla. 340/30 BC. Antikensammlung Kiel, inventory number B 895.", by Marcus Cyron, 2012, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Domestication of soybeans: "Common English name: soybeans; Name in Kanji: 穭豆; English translation of Kanji: second growth bean; Family: Leguminosae; Species: Glycine max (L.) Merr.; English description(s): soy beanGlycine max (L.) Merr.", by AnonymousUnknown author, 1804, licensed under CC BY 4.0, via Wikimedia Commons. View source. View in tree.
• Domestication of sugarcane: "Sugar cane. A plant, very reduced; B stem piece with leaf, reduced; C flower wasp, desi. ; 1 part of a panicle strip, enlarged; 2 flowers, the like; 2a flowers without skins, the like. ; 3 deck shells, desgl.; 4 lower cover shells, desgl.; 5 upper cover shells, desgl. ; 6 flower cover, desgl.", by Franz Eugen Köhler, Köhler's Medizinal-Pflanzen, 1897, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Domestication of the camel: "Exhibit in the Östasiatiska museet, Stockholm, Sweden. This artwork is old enough so that it is in the public domain. Photography was permitted in the museum without restriction.", by Daderot, 2014, licensed under CC0, via Wikimedia Commons. View source. View in tree.
• Domestication of the dog: "Hunting scene: dogs attack a mouflon.", by Alessandro Passaré, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Domestication of the donkey: "Model, donkeys with drivers, saddle bags", 2030, licensed under CC0, via Wikimedia Commons. View source. View in tree.
• Domestication of the horse: "Image of a horse from the Lascaux caves made by the Cro-Magnon peoples at their hunting route in the Stone age", 1050, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Domestication of vanilla: "Drawing of vanilla from the florentine codex (made in the 1580s)", by uploaded to Wikipedia by Maunus, 2008, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Domestication of wheat: "Painting of Ancient Egypt showing threshing of wheat.", by Carlos E. Solivérez, 2006, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Double-acting pin tumbler lock: "A Common type of pin tumbler lock, usually found in Europe.", by Willh26, 2016, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Double-action piston bellows: "line art drawing", by Pearson Scott Foresman, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Double-edge safety razor: "Front page of Gillette's razor patent.", by K. C. Gillette, 1904, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Double-slit experiment: "Young Diffraction.png", licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Dragline excavator: "Big Muskie dragline, Ohio coal strip mine, biggest mobile land machine in the world c.1969 For more information or additional images, please contact 202-586-5251.", by ENERGY.GOV, 2014, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Drawloom: "Japan; Fragment; Textiles-Woven", licensed under CC0, via Wikimedia Commons. View source. View in tree.
• Drink can: "Neuweiler Pilsner Beer Can - Allentown PA", by Self Scanned, 1940, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Drone: "Winston Churchill and the Secretary of State for War waiting to see the launch of a de Havilland Queen Bee radio-controlled target drone, 6 June 1941. The Prime Minister, Mr Winston Churchill, with Captain The Right Honourable David Margesson, Secretary of State for War, watching preparations being made in an unspecified UK location for the launch of a De Havilland Queen Bee seaplane L5984 from its ramp. The Queen Bee pilotless target drone was a radio-controlled version of the Tiger Moth trainer.", by War Office official photographer, Horton (Capt), 1941, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Drum: "Close-up detail of the Chinese painting Night Revels, handscroll, ink and colors on silk, 28.7 x 335.5 cm.", by Anonymous Song Chinese artist after the original by Gu Hongzhong, 1279, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Drum (container): "petroli car:", by Trevor MacInnis, 2005, licensed under CC BY-SA 2.5, via Wikimedia Commons. View source. View in tree.
• Dry cell: "Dry cell battery by Wilhelm Louis Frederik Hellesen. US patent 439151", by US Patent Office, Wilhelm Louis Frederik Hellesen, dead 1892., 1890, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Dry compass: "Kardanischer-Kompass.jpg", licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Dry dock: "Réparation et reconstruction du navire de commerce « La Ceres » en cale sèche, Dieppe, France, v. 1854-1855", by Paul-Émile Miot, 1854, licensed under CC BY 2.0, via Wikimedia Commons. View source. View in tree.
• Dry latrines: "Ancient Roman latrines / latrinae, Ostia Antica", by Fubar Obfusco, 2004, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Dry photographic plate: "Young Hawaiian Girl. 10 x 7 1/4 – inch toned gelatin silver print, 1909, signed in pencil on lower right. The print is dry mounted to a board.", by Caroline Haskins Gurrey, 1909, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Drywall: "Drywall Self-owned, released to PD", by Amaxson at English Wikipedia, 2005, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Duct tape: "A roll of silver, Scotch brand duct tape.", by Evan-Amos, 2010, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Dutch process cocoa: "Dutch process cocoa on the left and natural cocoa on the right.", by F_A, 2011, licensed under CC BY 2.0, via Wikimedia Commons. View source. View in tree.
• DVD: "DVD-R bottom side", by User:Wanted, User:Ochro, 2004, licensed under CC BY-SA 2.5, via Wikimedia Commons. View source. View in tree.
• Dye-sensitized solar cell: "Farbstoffsolarmodule der Größe 30 x 30 cm² in verschiedenen Designs und Farben. Die Verkapslung besteht aus chemisch und thermisch sehr stabilem Glaslot, um eine langzeitstabile Versieglung des Elektrolyten zu gewährleisten", by Ronald vera saavedra colombia (bogota)ISE;, 1997, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Dynamic random-access memory: "I the author of this drawing, release is under GFDL and creative commons. This is a schematic drawing of the two original designs of DRAM patented in 1968 in United States patent #3,387,286.", by Cyferz at English Wikipedia, 2007, licensed under CC BY 2.5, via Wikimedia Commons. View source. View in tree.
• Dynamite: "Tennessee Valley Authority. Construction of Douglas Dam. Placing a dynamite charge in a blast hole in bedrock at the site of TVA's new Douglas Dam on the French Broad River. This dam will be 161 feet high and 1,682 feet long, with a 31,600 acre reservoir area extending forty-three miles upstream. With a useful storage capacity of approximately 1,330,00 acre feet, this reservoir will make possible the addition of nearly 100,000 kilowatts of continuous power to the TVA system in dry years and almost 170,000 kilowatts in the average year", by Alfred T. Palmer, 1942, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Dynamo: "Drawing of Antonio Pacinotti's dynamo, an early electrical generator invented by Italian professor Antonio Pacinotti about 1860. It was first to use a doughnut shaped armature with many windings (16 in this machine) distributed evenly along its circumference to even out the output waveform, producing almost steady direct current. It was the inspiration for the Gramme dynamo, the first machine to produce power commercially for industry. This drawing is of a machine presented at the Paris Electrical Exhibition in 1867, from the caption: "Pacinotti machine at the Paris Electrical Exhibition". Alterations: removed caption and discoloration along bottom edge.", by The drawing is signed with two marginally legible names: 'L. LEGEA'(?) and 'J(?) CARTERET'. I haven't been able to find any information on either., 1884, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Dynamo self-excitation: "From the text: Fig 2770. Murray alternating current direct-connected unit with high speed Corliss engine and belt-driven exciter, 50, 75, 100 KVA alternator and 150 RPM engine. Note: This image is only about 3 inches wide and 1.5 inches tall in the book -- a testament to the high printed-image quality of these 90 year old engineering books that cost $1 per volume in 1917.", licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• E-reader: "Czytnik Sony LIBRIé EBR-1000", by Dale DePriest, 2007, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Earth oven: "Chauffage des pierres volcaniques", by Saga70, 2015, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Earth's circumference: "Illustration of the method Eratosthenes used to calculate the circumference of the Earth by CMG Lee. The map and globe are derived from http://commons.wikimedia.org/wiki/File:Egypt_sat.png and http://commons.wikimedia.org/wiki/File:Earth_orthographic_projection_Earthmap1000x500.jpg , respectively.", by cmglee, David Monniaux, jimht at shaw dot ca, 2005, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Ebonite: "Ebonit. Damklockkedja 1860-tal, medaljong ca 1870 och etui för tinotyp 1857", by FBQ, 2011, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• EEPROM: "AT24C02 EEPROM", by Nevit Dilmen (talk), 2014, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Egyptian blue: "Dendera Temple complex", by Panegyrics of Granovetter, 2020, licensed under CC BY-SA 2.0, via Wikimedia Commons. View source. View in tree.
• Egyptian wooden pin lock: "A diagram drawn by me (in Apple Pages!) which shows the mechanism of an old Egyptian lock LOCKED, similar to the modern day pin tumbler lock. See the diagram's sister of a Egyptian Lock Unlocked.", by Willh26, 2016, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Ejector seat: "Ejection Seats.", by Ejection_Seats_@_Deutsche_Museum_Flugwerft_Schleißheim.jpg: Vestman from Helsinki, Finland derivative work: Jon Ascton at en.wikipedia, 2010, licensed under CC BY 3.0, via Wikimedia Commons. View source. View in tree.
• Electret microphone: "Electret condenser microphone capsules.jpg", licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Electric arc: "This pic shows an arc between two nails.", by Achim Grochowski -- Achgro, 2005, licensed under CC BY 3.0, via Wikimedia Commons. View source. View in tree.
• Electric arc furnace: "Phosphate smelting furnace worker, Muscle Shoals fsac.1a35278u.jpg", by Alfred T. Palmer, 1942, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Electric arc steel furnace: "Original image description from the Deutsche FotothekMetallurge für Erzeugung-Stahl, E-Werk", by Eugen Nosko, 1980, licensed under CC BY-SA 3.0 de, via Wikimedia Commons. View source. View in tree.
• Electric car: "Le tricycle électrique de Gustave Trouvé, premier véhicule électrique de l'histoire qui fut exposé au public", by Jacques CATTELIN, 2016, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Electric chair: "Electric chair.jpg", licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Electric clock: "Exhibit in the Clockmakers' Museum - London, UK.", by Daderot, 1846, licensed under CC0, via Wikimedia Commons. View source. View in tree.
• Electric generator: "The Gramme machine or Gramme dynamo, an electrical generator designed by Belgian inventor Zénobe Gramme in 1871. It was the first machine to be used industrially to generate power. His innovation was to use many armature windings, wound on a doughnut shaped armature, and switched with a many segmented commutator, to smooth the output waveform, producing nearly constant DC power. This shows a hand cranked model from the 1870s designed for use in laboratories, it's output was equivalent to "eight ordinary Bunsen elements [batteries]". It used laminated permanent magnets invented by Jamin.", by Tamorlan, 2007, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Electric guitar: "Diagrams of Rickenbacker lap steel guitar design from 1934 patent application.", by George D. Beauchamp, 1934, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Electric locomotive: "Plakat für Robert Davidsons Electro-Magnetic Exhibition in London im Dezember 1842", by Unbekannter Grafiker, zweifellos vor mehr als 70 Jahren verstorben, 1842, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Electric motor: "An electric motor presented to Kelvin by James Joule in 1842, Hunterian Museum, Glasgow", by Stephencdickson, 2018, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Electric organ: "en:Telharmonium console by en:Thaddeus Cahill", by User Chris 73 on en.wikipedia, 1897, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Electric pen: "Thomas Edison's Electric pen.", 1850, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Electric shaver: "Ad for the Schick 20 electric shaver, printed in the Saturday Evening Post. Notable as the source for Neon Park's cover art for the Frank Zappa album Weasels Ripped My Flesh.", by Schick Incorporated, Stamford, Conn., 1953, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Electric stove: "Line drawings submitted on 29 November 1905 when David Curle Smith obtained an Australian patent (No. 4699/05) for his pioneering "electric cooking stove".", by David Curle Smith (Life time: 1859-1922), 1905, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Electric telegraph: "Elements of the subterranean electric telegraph built by Francis Ronalds in 1816", by Ronalds, F., 1823, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Electric toaster: "The D-12 Toaster, invented in 1909 by Frank Shailor of General Electric.", by Eric Norcross, 2009, licensed under CC BY 3.0, via Wikimedia Commons. View source. View in tree.
• Electric toothbrush: "A photo of a Motodent electric toothbrush. The toothbrush was on display at the the Museum of American Heritage and the photo was taken during a visit to the museum. The museum display mentioned an inventor, Tomlinson Moseley. There is a US patent that appears to cover the depicted electric toothbrush. The patent was filed for in 1937 and it indicates that the patent rights were assigned from Moseley to Motodent, Inc., of Los Angeles, California, USA.", by Gazebo, 2019, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Electric traffic light: "Traffic lights.jpg", licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Electric tram: "The world’s first electric tram, the Groß-Lichterfelde Tramway, began operation in 1881 in the Lichterfelde neighborhood of Berlin, Germany and was produced by Werner von Siemens. Direct current was supplied through the rails. The tram car is 5m long by 2m wide and weighs 4.8 tonnes. It travels at a maximum speed of 40 kilometres per hour and carries 20 people at a time. In the first three months of operation the tram had already carried 12,000 passengers.", by Unknown authorUnknown author, 1882, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Electric-powered submarine: "The Peral submarine, 1888.", by Unknown authorUnknown author, 1888, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Electrical tape: "Electrical tape, standard black", by Jonas Bergsten, 2005, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Electrocardiography machine: "In contrast to what the name of this file may suggest, this picture does not represent the ECG machine built by Willem Einthoven and his team. It shows an early commercial ECG machine, built in 1911 by the Cambridge Scientific Instrument Company (Christoph Zywietz, A Brief History of Electrocardiography - Progress through Technology; S. L. Barron, The development of the electrocardiograph in Great Britain, British Medical Journal 1:720, 25 March 1950) to measure the human electrocardiogram according to the standards developed by Einthoven.", licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Electroencephalography: "First published Electroencephalogram of a human. This image is one of the first EEGs, appearing in Berger's First Report. It is a portion of fig. 13 from Berger's first publication on EEG: Berger H. Über das Elektrenkephalogramm des Menschen. Archives für Psychiatrie. 1929; 87:527-70. This was later translated into English and republished: Berger H. On the Electroencephalogram of Man. Electroencephalogr Clin Neurophysiol. 1969;Suppl 28:37-73. PMID 4188918 It appears on page 58 of the translated version. The top trace is the EEG recorded from a young boy, the bottom trace is a 10 Hz frequency reference.", by Hans Berger, 1937, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Electroluminescence: "This image shows a replication of H.J. Round's experiments in which he discovered the effect underlying the light emitting diode (LED). A negatively charged needle contacts a positively charged crystal of silicon carbide or carborundum. At a voltage of 9 V and a current of 30 mA a green glow can be observed at the contact point between needle and crystal. A more detailed version of the setup can be found at www.dlip.de", by Biolippi, 2009, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Electrolysis: "Worlds largest Electrostatic generator at Teylers Museum (Haarlem, The Netherlands))", by McSmit, 2006, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Electrolysis of water: "Erste quantitative Wasserelektrolyse durch Johann Wilhelm Ritter, zuerst veröffentlicht in "Voigts Magazin für den neuesten Zustand der Naturkunde", Bd.2 (1800) S.356-400. Die Zeichnung wurde von Ritter selbst angefertigt und illustrierte den Artikel. Die Messbecher fangen das entweichende Gas auf und Ritter bestimmte erstmalig das Verhältnis von Wasserstoffgas (dort: Hydrogen) und Sauerstoffgas richtig mit 2:1.", by Original uploaded by Jazi (Transfered by LeastCommonAncestor), 2010, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Electrolytic detector: "An electrolytic detector, a primitive device used to demodulate radio waves in early radio receivers around the turn of the century. It consists of a metal cup containing a dilute solution of nitric acid and a fine platinum wire on an adjustable arm with the tip dipping in the acid.", by Unknown authorUnknown author, 1912, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Electromagnet: "Drawing of the first electromagnet, invented in 1824 by British scientist William Sturgeon. This was his original drawing from his 1824 paper to the British Royal Society of Arts, Manufactures, and Commerce. It was made of 18 turns of bare copper wire (insulated wire had not been invented) on a U-shaped lacquered iron core about 1 ft (30 cm) long and 1/2 inch (13 mm) diameter. When the wires were connected to a single cell copper-zinc-acid battery, the electromagnet could support 9 pounds. The little cups contain mercury and were an early method of making an electrical contact between wires. The one on the left acts as a power switch. Alterations to image: converted from JPG to 32color PNG.", by William Sturgeon, 1824, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Electromagnetic catapult: "Electromagnetic Aircraft Launch System", by Tosaka, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Electromagnetic induction: "Drawing of Michael Faraday's 1831 experiment showing electromagnetic induction between coils of wire, using 19th century apparatus, from an 1892 textbook on electricity. On the right is a liquid battery that provides a current that flows through the small coil of wire (A) creating a magnetic field. When the small coil is stationary, no current is induced. However, when the small coil is moved in or out of the large coil (B), the change in magnetic flux induces a current in the large coil. This is detected by the deflection of the needle in the galvanometer instrument (G) on the left.", by J. Lambert, 1892, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Electromechanical programmable computer: "German Museum of Technology, Berlin, Germany.", by Photograph by Mike Peel (www.mikepeel.net)., 2017, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Electromechanical relay: "Delta Electronics DPS-350FB A - board 1 - OEG SDT-SS-112M - case removed", by Raimond Spekking, 2021, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Electron: "A diagram presented by J. J. Thomson to show how he believed electrons are arranged in atoms. (Royal Institution of Great Britain, March 1905)Excerpt:Let us now consider the kind of atom we could build up out of corpuscles and positive electricity. The mathematical investigation of this problem leads to the following results. The simplest atom containing 1 corpuscle would have 1 corpuscle at the centre of the sphere of positive electrification; the 2 corpuscle atom would have the 2 corpuscles separated by a distance equal to the radius of this sphere; the 8 corpuscle atom would have the 3 corpuscles at the points of an equilateral triangle, whose side is equal to the radius of the sphere; 4 corpuscles would be at the corners of a regular tetrahedron, whose side is equal to the radius of the sphere; 5 corpuscles are situated, 4 at the corners and 1 at the centre of a tetrahedron; 6 at the corners of an octahedron; 7 and 8 are more complicated, as the simplest arrangements for 7 and 8, an octahedron with 1 at the centre and a cube, are both unstable; and for 7 we have a ring of 5 in one plane with 2 on a line through the centre at right angles to the plane; and 8 we have the octahedron with 2 inside.", by J. J. Thomson, 1905, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Electron microscope: "The First Commercial Electron Microscope sold, having a Resolving Power Higher than that of a Light Microscope Ernst Ruska, Berlin 1939 designed 1938, first machine sold by Siemens to IG Farben. For the first time the apparatus had a condensor in front of the specimen and two magnifying lenses. Magnification is around 12,000 times", by J Brew, uploaded on the English-speaking Wikipedia by en:User:Hat'nCoat., 2006, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Electronic calculator: "Anita Mk VIII calculator. Photograph taken by myself of a machine in my collection.", by MaltaGC at English Wikipedia, 2007, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Electronic cigarette: "The copyright of electronic cigar(first generation) of Ruyan is protected by Ruyan group holding ltd and.The picture illustrates the electronic cigar(first generation) of the company which is described in this article.I've got permission to release it", by Jodanw22 at English Wikipedia, 2008, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Electronic digital computer: "Atanasoff-Berry Computer at Durham Center, Iowa State University", by User:Manop, 2006, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Electronic general purpose computer: "Two pieces of ENIAC currently on display in the Moore School of Engineering and Applied Science, in room 100 of the Moore building. Photo courtesy of the curator, released under GNU license along with 3 other images in an email to me. Copyright 2005 Paul W Shaffer, University of Pennsylvania. On the left is a function table (for reading in a table of data). There are four panels, the left-most one controls the interface to the function table. The third one is an accumulator - memory for storing a 10-digit number, which can be added into.", by The original uploader was TexasDex at English Wikipedia., 2006, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Electronic paper: "Microcapsules used in the e-ink display of a Kindle 3. Lens was focussed just below the surface of the screen in order to show the microcapsules.", by Gijs.noorlander, 2010, licensed under CC BY 3.0, via Wikimedia Commons. View source. View in tree.
• Electronic television: "Subject: Zworykin, V. K (Vladimir Kosma) 1889-1982        Birt, Mildred        Westinghouse Electric & Manufacturing Company Type: Black-and-white photographs Date: 1934 Topic: Television Local number: SIA Acc. 90-105 [SIA2010-1667] Summary: Vladimir Kosma Zworykin (1889-1982), a Westinghouse Electric and Manufacturing Company research engineer, is shown demonstrating his new cathode ray television set which can entertain large groups instead of one or two spectators. Miss Mildred Birt is the interested watcher. The broadcast images are projected on a mirror on the top of the cabinet making it possible for many to watch Cite as: Acc. 90-105 - Science Service, Records, 1920s-1970s, Smithsonian Institution Archives Persistent URL:http://siris-archives.si.edu/ipac20/ipac.jsp?&profile=all&source=~!siarchives&uri=full=3100001~!289412~!0#focus Repository:Smithsonian Institution Archives View more collections from the Smithsonian Institution.", by Smithsonian Institution from United States, 2010, licensed under No restrictions, via Wikimedia Commons. View source. View in tree.
• Electrostatic generator: "Figure V and VI from Ottonis De Guericke Experimenta Nova (ut vocantur) Magdeburgica De Vacuo Spatio, Amstelodami: Janssonius, 1672, p. 148, showing Guericke's experiments with the sulfur globe.", by Otto von Guericke, 1672, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Electrotachyscope: "Picture of Ottomar's Anschütz's electrotachyscope published in "American Scientific" (1889)", by Unknown authorUnknown author, 1889, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Electrotherapy: "Woodcut illustration from "De l'électrisation localisée et de son application a la pathologie et a la thérapeutique" by Duchenne.", by Cabinet of Art and Medicine, 2011, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Electrotyping: "Schematic apparatus for electrotyping. An electrical current flows from the battery, through the copper anode connected to the positive terminal of the battery, through the electrolyte, and into the coated mold (the cathode). A copper film (the electrotype) grows onto the electrically conducting coating of the mold.", by Easchiff, 2011, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Electrum: "Cup Idalion Louvre N3455.jpg", by Marie-Lan Nguyen, 2007, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Elephant clock: "The elephant clock from Al-Jazari's manuscript.", by Al-Jazari, 1315, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Elevator: "Elevator", by Unknown illustrator, 1450, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Email: "Reading e-mail in Evolution 3.6.2 on GNOME 3.6.2. The operating system is Fedora 18.", by AlexanderVanLoon, 2013, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Embroidery: "Detail of an embroidered silk gauze ritual garment from a 4th century BC, Zhou era tomb at Mashan, Hubei province, China. The flowing, curvilinear design incorporates dragons, phoenixes, and tigers. Rows of even, round chain-stitches are used both for outline and to fill in color.", by PericlesofAthens, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Endless chain drive: "The oldest known illustration of an endless power-transmitting chain drive. This was illustrated in 1092, during the Song Dynasty, by the Chinese engineer Su Song in his book Xinyi Xiangfayao. It was called the "celestial ladder", and was used for coupling the main driving shaft of his clock tower to the armillary sphere gear box (which was mounted at the top of the tower in Kaifeng).", by Su Song 蘇頌, 1092, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Enigma machine: "Macchina crittatrice e decrittatrice. Esposta presso il museo nazionale della scienza e della tecnologia "L. Da Vinci" di Milano. La macchina Enigma si presenta come una scatola metallica scura con, sul lato superiore, una tastiera riportante 26 lettere posta inferiormente rispetto ad una sua esatta riproduzione in versione di "spie luminose" (visore), tali, cioè, che una lettera della tastiera superiore si illumina ogni qualvolta viene premuto un tasto in quella inferiore. Aprendo la macchina, sotto il visore sono visibili 28 portalampade: 26 per illuminare le lettere del visore prima descritto, 1usato come provalampade e 1 come tester. Superiormente alla "tastiera luminosa" sono posizionate a sinistra tre feritoie, da ciascuna delle quali si affaccia la corona dentata (anello) di un disco (rotore, tre in tutto) e una corrispondente finestrella che mostra la cifra di un contatore, e a destra un selettore meccanico. Frontalmente, la macchina presenta un pannello (steker) a 52 plug o prese, ove sono inseribili degli spinotti per il completamento di circuiti elettrici (collegamenti tra tastiera e primo rotore).", by Alessandro Nassiri, 2012, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Epinephrine (medication): "Skeletal formula of epinephrine (also known as adrenaline or adrenalin) — a hormone secreted by adrenal medulla.", by Roland Mattern, 2009, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Epinephrine autoinjector: "This is a picture of an Epi-Pen acquired in 2016 and is the latest version in the USA that I am aware of as of the upload date.", by Tokyogirl79, 2016, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Epoxy resin: "A tube of 5-minute epoxy", by Taktoa, 2010, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• EPROM: "4Mbit EPROM Texas Instruments TMS27C040", by yellowcloud from Germany, 2010, licensed under CC BY 2.0, via Wikimedia Commons. View source. View in tree.
• Eruptor: "An "eruptor" as depicted in the Huolongjing. Essentially a fire lance on a frame, the 'multiple bullets magazine eruptor' shoots lead shots, which are loaded in a magazine and fed into the barrel when turned around on its axis. As depicted in the Huolongjing", by Yprpyqp, 1390, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Escalator: "Eugene Wemlinger. Luna Park, Coney Island, 1909. Nitrate negative, 3 1/2 x 5 1/2 in. (8.9 x 14 cm). Prints, Drawings and Photographs. Brooklyn Museum/Brooklyn Public Library, Brooklyn Collection, 1996.164.10-23. (1996.164.10-23_bw_SL1.jpg) Thank you, Rob Ketcherside! This image has been geotagged by Rob Ketcherside so Brooklyn could be part of the Historypin launch on July 11, 2011. Want to help? See if you can place any of these images on a map! More about #mapBK: www.brooklynmuseum.org/mapbk", by Brooklyn Museum, licensed under No restrictions, via Wikimedia Commons. View source. View in tree.
• Espresso machine: "First patent (vol. 33 n. 256) for the Espresso Machine, by Mr. Angelo Moriondo, dated May 16, 1884 and titled "Nuovi apparecchi a vapore per la confezione economica ed istantanea del caffè in bevanda. Sistema A. Moriondo"", by Mr. Angelo Moriondo, 1884, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Excimer laser: "Summit Technology Inc (Boston) Excimer laser 1988", by IoOALP, 2002, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• External DC defibrillator: "A circuit diagram showing the simplest (non-electronically controlled) defibrillator design, depending on the inductor (damping), producing a Lown, Edmark or Gurvich Waveform.", by Wolfmankurd at English Wikipedia, 2007, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Extreme ultraviolet lithography: "Top: EUV multilayer and absorber (purple)constituting mask pattern for imaging a line. Bottom: EUV radiation (red) reflected from the mask pattern is absorbed in the resist (amber) and substrate (brown), producing photoelectrons and secondary electrons (blue). These electrons increase the extent of chemical reactions in the resist, beyond that defined by the original light intensity pattern. As a result, a secondary electron pattern that is random in nature is superimposed on the optical image. The unwanted secondary electron exposure results in loss of resolution, observable line edge roughness and linewidth variation. Refs.: N. Felix et al., Proc. SPIE 9776, 97761O (2016); A. Saeki et al., Nanotech. 17, 1543 (2006); T. Kozawa et al., JVST B 25, 2295 (2007).", by 2pem, 2014, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Eyeglasses: "The "Glasses Apostle" painting in the altarpiece of the church of Bad Wildungen, Germany. Painted by Conrad von Soest in 1403, "Glasses Apostle" is considered the oldest depiction of eyeglasses north of the Alps.", by Conrad von Soest, 1403, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Fahrenheit scale: "Thermometer with Fahrenheit and Celsius units", by Stilfehler, 2006, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Fast potter's wheel: "Workshop of a potter. Side A of a Corinthian black-figure pinax, ca. 625–600 BC. From Penteskouphia.", licensed under CC BY 2.5, via Wikimedia Commons. View source. View in tree.
• Fax machine: "Infotec 6000 Fernkopierer", by Benutzer:Terramobil, 2007, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Ferris wheel: "The original Ferris Wheel at the 1893 World Columbian Exposition in Chicago.", by Unknown authorUnknown author, 1893, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Ferrocement: "brignoles bateau en ciment armé inventé par Lambot", by Jorune, 2012, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Ferrofluid: "A superparamagnetic fluid, otherwise known as a ferrofluid, in a dish over a neodymium magnet.", by Steve Jurvetson, 2006, licensed under CC BY 2.0, via Wikimedia Commons. View source. View in tree.
• Fiberglass: "Examples of glass filler (microspheres) and glass material (cut fibers and two fabrics) for plastics reinforcement: glass microspheres (or glass beads); diameter: about 300 µm, specific gravity: 2.5. Mineral filler mainly used to increase the stiffness of a thermoset resin and to make road safety markings; 5 mm length chopped strands of fiberglass used to reinforce thermoset resins; fibrous reinforcements for thermoset resins: two glass fabrics with different area density; fiber orientation: 0 and 90° (most common): weave pattern: taffeta (down left, area density: 550 g/m2), and 2x2 twill (down right, area density: 280 g/m2).", by Cjp24, 2009, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Field-effect transistor (concept): "Cross-sectional view of a field-effect transistor, showing source, gate and drain terminals", by VectorVoyager PNG version: user:rogerb, 2023, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Field-programmable gate array: "Xilinx Spartan FPGA die shot.jpg", licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Fierce-fire oil cabinet: "An 12th century Chinese flamethrower with a tank for petrol-like fluid (most likely Greek Fire that had been known to the Chinese since the early 10th century) and double-acting pump with two pistons so that it fires a continuous and unbroken stream of flame. This illustration originally appeared in the Wujing Zongyao military manuscript written in the year 1044 during the Song Dynasty of China. This picture also appears in Joseph Needham's book Science and Civilization in China: Volume 5, Chemistry and Chemical Technology, Part 7, Military Technology; the Gunpowder Epic.", by PericlesofAthens, 2007, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Fighter aircraft: "Vickers FB.5 Gunbus flying replica G-ATVP, painted as 2345 of the Royal Flying Corps, at Yeovilton in 1966", by RuthAS, 1966, licensed under CC BY 3.0, via Wikimedia Commons. View source. View in tree.
• Finery forge: "Chinese iron workers smelting iron ore to make pig iron and wrought iron. This illustration is only half of the picture showing the puddling process, while the right half (not shown) displays men operating a blast furnace. This illustration is an original from the Tiangong Kaiwu encyclopedia printed in 1637, written by the Ming Dynasty encyclopedist Song Yingxing (1587-1666). Picture taken on the web from http://www.uni-tuebingen.de/uni/ans/project/conference/workshop.html. The picture also appears in Figure 14-10 on page 250 of E-tu Zen Sun and Shiou-Chuan Sun's translation of the Tiangong Kaiwu encyclopedia (Pennsylvania State University Press, 1966).", by See above, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Fire arrow: "An arrow strapped with gunpowder fired from a bow, from the Huolongjing", by Jiao Yu and Liu Bowen, 2017, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Fire engine: "Small stirrup pump, which could be operated by one person. Engraving from the mid-17th Century fire museum in Salem at Lake Constance, Germany. Perhaps the simplest form of bucket tub type fire engine", by Flominator (talk), 2010, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Fire hydrant: "New Orleans: 1869 patent model Birdsill Holly fire hydrant still in place streetside. Photo by Infrogmation of New Orleans, March 2007. Related images of same hydrant: Image:1869BirdsillHollyHydrantBayouStJohn.jpg, Image:1869BirdsillHollyHydrantFront.jpg Image:1869BirdsillHollyHydrantTop.jpg", by Photo by Infrogmation of New Orleans, March 2007., 2007, licensed under CC BY 2.5, via Wikimedia Commons. View source. View in tree.
• Fire lance: "Detail of the Dunhuang Mara Buddha, showing the fire lance and grenade", by Unknown authorUnknown author, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Fire piston: "A fire piston. A tiny piece of flash cotton, within a clear cylinder, is ignited by the heat of sudden (adiabatic) compression.", by Chocolateoak, 2010, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Fired bricks: "a brick", by Andrewlister, 2010, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Fireworks: "A VIEW of the FIRE-WORKES and ILLUMINATIONS at his GRACE the Duke of RICHMOND'S at WHITEHALL and on the River Thames on Monday 15 May 1749. Performed by the direction of Charles Fredrick Esq. Hand coloured etching showing the Royal Fire-workes and Illuminations in Whitehall and on the River Thames on Monday 15 May 1749. The occasion for which George Frideric Handel composed his Music for the Royal Fireworks. The firework display was for the benefit of King George II of Great Britain to celebrate the signing of the treaty at Aix la Chapelle in 1748 marking the end of the War of Austrian Succession. Unfortunately, during the display, one of the fireworks landed on the pavilion of the Temple of Peace, igniting the several thousand fireworks inside and killing three spectators.", 1749, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Fischer–Tropsch process: "Das Krupp-Treibstoffwerk in Wanne-Eickel um 1953, rechts hinten ist der Malakowturm von Hannibal 2 zu erkennen", by 1857Use, 2023, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Fish hook: "Shell fish hook.", licensed under CC BY 4.0, via Wikimedia Commons. View source. View in tree.
• Fishing net: "Some of the remains of the Paleolithic Antrea net.", by Sakari Pälsi, 1920, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Fishing reel: "Close-up detail of Song Dynasty Chinese painter Ma Yuan's Angler on a Wintry Lake, featuring the oldest known depiction of a fishing reel.", by Ma Yuan, 1195, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Flash memory: "A SanDisk Cruzer Titanium drive opened after being nearly destroyed.", by Nrbelex, 2005, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Flash powder: "1909 Victor (Smith-Victor) flash lamp 1903 View camera", by Race Gentry, 2009, licensed under CC BY-SA 2.0, via Wikimedia Commons. View source. View in tree.
• Flashlight: "1899 Eveready flashlight", by Doug Coldwell, 2009, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Flexography: "en:Flexography printing plate relief (closeup shot)", by en:user:Celshader, 2005, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Flintlock musket: "Page showing musketeer (Plate 4) from Jacob van Gheyn's Wapenhandelingen van Roers, Musquetten ende Spiessen, (1608)", by Jacob de Gheyn II, 1608, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Float glass: "C Palace station taken by C Ford, march 04.", by The original uploader was Secretlondon at English Wikipedia., 2004, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Floating dry dock: "Floating dock. Woodcut included in the booklet Descrittione dell’ artifitiosa machina. Printed in Venice in 1560.", by AnonymousUnknown author, 1560, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Floating-gate MOSFET: "Sectional view of a floating gate transistor", by Д.Ильин en-text: user:Wdwd, 2015, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Floating-point arithmetic: "A diagram/example showing the representation of a floating point number using a mantissa (aka significand) and an exponent.", by Sss41, 2012, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Floppy disc: "8-inch, 5,25-inch, and 3,5-inch floppy disks", by George Chernilevsky, 2009, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Fluid catalytic cracking: "Photo of a typical fluid catalytic cracker used in a petroleum refinery. Other information The photo was included in Exhibit 99.1 of the 8-K filing of the Valero Energy Corporation/TX, dated July 6, 2007, provided to the Securities and Exchange Commission (SEC) which is an agency of the U.S. Federal Government.", by Valero Energy Corporation/TX, 2007, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Fluked anchor: "Museo delle Navi, ancora antica, Nemi, Roma", by Pippo-b, 2007, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Fluorescent lamp: "Thirty Fluorescent lamps with reflections giving the impression of many more lamps, in Shinbashi, Tokyo, Japan", by Flickr user Oimax This image was originally posted to Flickr by OiMax at https://www.flickr.com/photos/72396314@N00/404614118. It was reviewed on 20 May 2007 by FlickreviewR and was confirmed to be licensed under the terms of the cc-by-2.0. 20 May 2007, 2007, licensed under CC BY 2.0, via Wikimedia Commons. View source. View in tree.
• Fluorine (isolation): "Figure 5 de Recherches sur l’isolement du fluor, page 41", by Henri Moissan et E. Peuchot, 1887, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Flush toilet: "Bramah's water closet, 1778", by Joseph Bramah, 1778, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Flute: "Bone flute dated in the Upper Paleolithic from Geissenklösterle, a german cave on the Swabian region. Replica.", by José-Manuel Benito, 2007, licensed under CC BY-SA 2.5, via Wikimedia Commons. View source. View in tree.
• Fluyt: "Wenceslas Hollar - A Flute (State 2).jpg", by Wenceslaus Hollar, 1607, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Flying bomb: "For documentary purposes the German Federal Archive often retained the original image captions, which may be erroneous, biased, obsolete or politically extreme. V1 vor dem Start Aus guter Deckung wird "V1" an die Abschußstelle gerollt. Der Start erfolgt durch eine Pressluftanlage. Mit Hilfe eines Fernlenkverfahrens trifft die "V1" das befohlene Ziel. Die gleichbleibend hohe Geschwindigkeit, die von keinem Feindjäger erreicht wird, erhält "V1" von einem Raketenantrieb. Diese erste deutsche Vergeltungswaffe ist eine hervorragende Schöpfung unserer Luftrüstung. Foto: PK-Lysiak/Transocean-Europapress", by Lysiak, 1944, licensed under CC BY-SA 3.0 de, via Wikimedia Commons. View source. View in tree.
• Flying cash: "Tradesmen, Tang dynasty, Bezeklik Thousand Buddha Caves, China. Painted on south wall in cave #45, 0.64 x 1.14 m.", by Unknown authorUnknown author, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Flying shuttle: "Curler. Wood, metal. Unknown place of origin, unknown date. Donor: unknown. Collection of the Immigration Museum of São Paulo.", by Conrado Secassi, 2016, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• FM radio: "First broadcast FM radio station W2XMN built by Edwin Armstrong in 1938 in Alpine, New Jersey, USA. The insets show a portion of the transmitter, and a map of Armstrong's network of FM stations in 1940.", by E. W. Murtfeldt, 1940, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Focal plane tomography: "Panoramicfilm.JPG", licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Fountain: "This image was provided to Wikimedia Commons as a contribution from an art & design school thanks to a collaboration between Llotja and Amical Wikimedia.", by Eme Chicano, 2014, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Fountain pen: "This photograph was taken with a Panasonic Lumix DMC-G85/G80", by Petar Milošević, 2017, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Four-stroke engine: "An American internal combustion otto engine", by Unknown authorUnknown author, 1880, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Fourdrinier machine: "Fourdrinier paper machine, Frogmore Mills This is a very historic site and was apparently where this machine (not this particular one) was first used in the UK in 1803. This more modern machine is operated by a charitable trust and is still in use. It is of great interest as it is driven by a steam engine - one of very, very few still in commercial service in the UK.", by Chris Allen, 2007, licensed under CC BY-SA 2.0, via Wikimedia Commons. View source. View in tree.
• Fourneyron turbine: "Fourneyron-Turbine im Deutschen Museum in München Details: http://www.deutsches-museum.de/sammlungen/maschinen/kraftmaschinen/wasserturbinen/fourneyron-turbine-1834/", by Ordercrazy, 2012, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Fracking: "Fracking the Bakken Formation in North Dakota", by Joshua Doubek, 2011, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Fractional distillation: "Fractional distillation lab apparatus.", by Original: Theresa knott (talk · contribs) Derivative work: John Kershaw (talk · contribs), 2008, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Fragmentation bomb: "An illustration of a fragmentation bomb from the 14th century Ming Dynasty book Huolongjing. The black dots represent iron pellets. Text on left: 中藏铁子神砂 (Iron pellets inside [are] magical grit), Text on right: 爛骨火油神砲 (Bone crushing petroleum magical artillery [shell]).", by Jiao Yu and Liu Ji, 1350, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Francis turbine: "Francis turbine inlet scroll, Grand Coulee Dam", by U.S. Bureau of Reclamation, 1941, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Franklin stove: "A Franklin stove.", by unknown (NPS?), licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Frequency analysis: "Al-kindi-cryptanalysis.png", licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Friction match: "A Congreve matchbox (1827, made of tin)", by Cassell & Co., 1900, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Frog pregnancy test: "Example of a xenopus frog used as a pregnancy test", by Lisa Jean Moore, 2016, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Froth flotation: "A 3D render of a froth flotation cell", by Dhatfield, 2001, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Fuel cell: "Fuel cell NASA p48600ac.jpg", licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Full plate armour: "Men at arms / Gendarme armor at the metro museum in NYC", by Michelle Lee, 2012, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Fuller's earth: "Multani Mitti is a special earth from Multan, Punjab, Pakistan", by Khalid Mahmood, 2011, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Fulling mill: "Engraving of a fulling mill from Theatrum Machinarum Novum (Theatre of New Machines) by", by Georg Andreas Böckler, 1661, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Fully mechanical clock: "L'astrario di Giovanni Dondi è un orologio astronomico che mostra l'ora, il calendario annuale, il movimento dei pianeti, del Sole e della Luna. Il meccanismo è mosso da un orologio collocato nella parte inferiore della struttura. L'orologio è regolato da un bilanciere con scappamento a verga azionato da un motore a pesi con un sistema di contrappeso denominato "volgi e svolgi". Il bilanciere compie un battito ogni due secondi. Questo dato si deduce dagli ingranaggi dell'orologio. Esso è composto infatti di tre ruote: ruota maestra di 120 denti, seconda ruota di 80 denti con pignone di 12 ali, ruota scappamento di 27 denti con pignone di 10 ali. Coassiale e fissata alla ruota maestra, vi è una ruota di 24 denti che ingrana in una ruota di 20 denti, il cui pignone di 12 ali fornisce il moto alla sfera oraria di 144 denti. Il quadrante, la cosiddetta "Sfera Oraria", mostra le ore secondo una suddivisione in 24, di conseguenza la ruota deve compiere un giro completo in un giorno La ruota maestra è sua volta collegata con diversi ingranaggi ai quadranti posti nella parte superiore della struttura. I sette quadranti rappresentano i movimenti dei pianeti allora conosciuti (Marte, Mercurio, Venere, Giove, Saturno), del "Primo Mobile", che descrive il moto delle stelle fisse, e della Luna. Sotto quest'ultimo si trova un ulteriore quadrante che riporta la posizione del nostro satellite rispetto a quella del Sole e permette di calcolare le date delle eclissi (la cosdetta Linea dei nodi). La lettura della posizione dei pianeti avviene rispetto ad una doppia scala graduata: scala dei mesi (mobile) e scala dello zodiaco (fissa); la scala dei mesi mobile può essere aggiustata rispetto al disco più interno per aggiustare la data indicata rispetto a quella siderale Al centro della struttura una grande ruota svolge la funzione di calendario riportando, sul bordo esterno, i giorni di ciascun mese dell'anno. Per ogni giorno sono indicati l'ora dell'alba e del tramonto (alla latitudine di Padova), la "lettera domenicale" che determina la successione dei giorni della settimana e il nome dei santi e la data delle feste fisse della Chiesa. La lettura del giorno si effettua attraverso un'apposita feritoia laterale. Notizie storico-critiche I quadranti dei pianeti, della Luna e del "Primo Mobile" realizzano meccanicamente i principi dell'astronomia tolemaica, che supponeva la Terra immobile, al centro dell'Universo. La teoria originale, dovuta ad Eudosso (408 a.C. - 355 a.C.), vede la Terra circondata da sfere concentriche che contengono ciascuna un pianeta. L'ultima sfera, quella più esterna, il "Primo Mobile" era quella che riceveva il movimento per volontà divina e lo trasmetteva a sua volta a tutte le altre sfere. Lo schema originale fu successivamente perfezionato, per arrivare a spiegare le anomalie dei movimenti dei Pianeti (i cosiddetti "moti retrogradi"), fino ad arrivare alla teoria elaborata da Tolomeo (100 ca. - 175 ca.) in cui il moto degli astri è realizzato utilizzando un sistema di epicicli - la circonferenza su cui si spostano i pianeti - il cui centro si muove a sua volta lungo una circonferenza più grande, il deferente, fissa intorno alla Terra L'orologio originale fu costruito nella seconda metà del 1300, presumibilmente tra il 1365 e il 1384, secondo la datazione più accreditata basata sui riferimenti astronomici riportati dal Dondi per la costruzione del suo complesso meccanismo. Le ultime notizie relative all'oggetto risalgono al 1529 quando viene citato in occasione dell'arrivo in Italia di Carlo V, re di Spagna e Imperatore del Sacro Romano Impero. Riportato ormai come in cattivo stato di conservazione e necessitante di manutenzione, andò presumibilmente distrutto negli anni successivi Il Tractus Astrarii scritto da Giovanni Dondi riporta fedelmente il lavoro di progettazione e costruzione dell'orologio astronomico. La copia di questo testo, conservata presso la Biblioteca Capitolare di Padova, ne ha permesso la ricostruzione in epoca moderna.", by Pippa Luigi (costruttore), 1961, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Fulminate-based firearm: "Lepage_silex_gun_dite_du_Premier_Consul_circa_1800", by PHGCOM, 2007, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Fulminates: "Highly purified mercury(II) fulminate orthorhombic crystals in a glass dish.", by Paramilitary at German Wikipedia (Original text: Tobias Maximilian Mittrach), 2006, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Functional magnetic resonance imaging: "http://fmrif.nimh.nih.gov/public/research NIMH is a US government agency. The logos at the tail end of the fmrif website note the agencies involved (http://fmrif.nimh.nih.gov/public/about): http://www.nimh.nih.gov/ http://www.ninds.nih.gov/ http://www.niaaa.nih.gov/ http://www.nih.gov/ http://www.dhhs.gov/ All are US government agencies. The paper this image is taken from was submitted by researchers at NIMH (all authors), working using fMRIF's 3 T GE scanner (see http://fmrif.nimh.nih.gov/public/research). The abstract of the paper is here: https://www.ncbi.nlm.nih.gov/pubmed/11577229?dopt=Abstract", by National Institute of Mental Health, 2012, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Functional programming language: "lisp program", by Green1jeet, 2015, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Fused filament fabrication: "it's a 3d printer", by John Abella, 2013, licensed under CC BY 2.0, via Wikimedia Commons. View source. View in tree.
• Galilean moons: "Jupiter and Moons through a 10" lx200 telescope", by Jan Sandberg, licensed under Attribution, via Wikimedia Commons. View source. View in tree.
• Galleon: "A Naval Encounter between Dutch and Spanish Warships", by Cornelis Verbeeck, 1618, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Galley: "An engraving of a French galley with sails from Plan de Plusieurs Batiments de Mer avec leurs Proportions (c. 1690). Engraving by Claude Randon.", by Henri Sbonski de Passebon, 1690, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Gallium: "Crystals of 99.999% gallium.", by en:user:foobar, 2004, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Gallium arsenide: "A pristine 2-inch single crystal gallium arsenide wafer with a (100) surface orientation. Purple features are a reflection of a nitrile glove.", by La2O3, 2014, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Gallium nitride: "Monocrystal of gallium nitride", by Opto-p, 2005, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Galvanometer: "Sine and Tangent Galvanometer-MHS 98-IMG 3874-gradient.jpg", by Rama, 2018, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Gas centrifuge: "Cascade of gas centrifuges used to produce enriched uranium. This photograph is of the U.S. gas centrifuge plant in Piketon, Ohio from 1984.", by U.S. Department of Energy, 1984, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Gas mantle: "A Coleman white gas lantern mantle burning at its highest setting.", by Fourpointsix at English Wikipedia, 2008, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Gas mask: "Indian infantry in the trenches, prepared against a gas attack [Fauquissart, France].", by H. D. Girdwood, 1915, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Gas stove: "Gas stove from 1851", by Mrs Beeton (Life time: 19th cent), 1904, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Gas turbine: "Sketch of John Barber's gas turbine, from his patent", by John Barber himself, 1791, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Gaseous diffusion: "Infographic from 2018-2019 Information Digest, NUREG 1350, Volume 30. Published in August 2018. For More Information go to: <a href="https://www.nrc.gov/reading-rm/doc-collections/nuregs/staff/sr1350/" rel="noreferrer nofollow">2018-2019 Information Digest</a> Visit the Nuclear Regulatory Commission's website at <a href="http://www.nrc.gov/" rel="noreferrer nofollow">www.nrc.gov/</a>. Photo Usage Guidelines: <a href="https://www.flickr.com/people/nrcgov/">www.flickr.com/people/nrcgov/</a> Privacy Policy: <a href="http://www.nrc.gov/site-help/privacy.html" rel="noreferrer nofollow">www.nrc.gov/site-help/privacy.html</a>. For additional information, or to comment on this photo contact: <a href="mailto:opa.resource@nrc.gov" rel="noreferrer nofollow">OPA Resource</a>.", by Nuclear Regulatory Commission from US, 2018, licensed under CC BY 2.0, via Wikimedia Commons. View source. View in tree.
• Gatling gun: "Gatling gun.jpg", licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Gears: "Shaanxi Provincial Museum, Xi'an, Han Gallery, 2009 visit. Complete indexed photo collection at WorldHistoryPics.com.", by Gary Todd from Xinzheng, China, 2009, licensed under CC0, via Wikimedia Commons. View source. View in tree.
• Geissler tube: "An illustration of Geissler gas-discharge tubes from the book "Les phénomènes de la physique" (1868) by Amédée Guillemin", by Amédée Guillemi, 1868, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Genaille–Lucas rulers: "A complete set of Genaille–Lucas rulers, with an index ruler. Derivative works of this file:  Genaille–Lucas ruler close-up.svg", by Worrydream, 2010, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Gene therapy: "Gene therapy.jpg", licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• General anesthesia: "Portrait of the physician Hua Tuo from a Qing Dynasty edition of The Romance of the Three Kingdoms.", by Unknown authorUnknown author, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• General relativity: "Video simulation of the view which would be seen by a close observer, of the final merger of GW150914, showing the distortion of the star-field from gravity as the black holes orbit and merge.", by Simulating eXtreme Spacetimes Lensing (SXS), 2016, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Generative adversarial network: "Generative adversarial network", by Zhang, Aston and Lipton, Zachary C. and Li, Mu and Smola, Alexander J., 2023, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Genetically modified animal: "A laboratory mouse in which a gene affecting hair growth has been knocked out (left), is shown next to a normal lab mouse.", by Maggie Bartlett, NHGRI., 2006, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Genetically modified food: "عالم النبات اثاناسيوس ثيولوجيس يقارن طماطم فلوريدا مع التي زرعها في بيته الزجاجي وكلاهما يحوي جين ACC", by Jack Dykinga, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Genetically modified organism: "Low-temperature electron micrograph of a cluster of E. coli bacteria, magnified 10,000 times. Each individual bacterium is oblong shaped.", by Photo byfkfkrErbe, digital colorization by Christopher Pooley, both of USDA, ARS, EMU., 2005, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Genetically modified plant: "نبتة تبغ نيكوتيانا", by Photo by and (c)2006 Derek Ramsey (Ram-Man), 2006, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Geordie lamp: "Plate 1 and descriptive text for this and plate 2 (also uploaded) from page 32-33 of Report Upon the Claims of Mr. George Stephenson, Relative to the Invention of His Safety Lamp, by the Committee Appointed at a Meeting Holden in Newcastle November 1st 1817, original tract held in the North of England Institute of Mining and Mechanical Engineers and uploaded with the authority of their librarian Jennifer Hillyard.", by Report Upon the Claims of Mr. George Stephenson, Relative to the Invention of His Safety Lamp, by the Committee Appointed at a Meeting Holden in Newcastle, November 1st 1817, 2013, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Germanium: "12 grams polycrystalline germanium, 2*3 cm.", by Jurii, 2009, licensed under CC BY 3.0, via Wikimedia Commons. View source. View in tree.
• Gilchrist–Thomas process: "Thomasbirne am Phoenixsee", by Rainer Halama, 2011, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Gimbal: "kardanupphängning", by Svjo, 2015, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Gittern: "Medieval painting of guitarra latina (left) and guitarra morisca (right) from the Cantigas de Santa Maria (13th. century)", by Unknown artistUnknown artist, 2012, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Glass: "Roman glass beaker from second half of the 4th century. Found in Cologne, now in the Staatliche Antikensammlung Munich. The style is called diatret, there are only 50 beakers left, most are broken. The characters at the top: "Bibe multis annis" short for "Bibe vivas multis annis" (Drink and you will live for many years"). Photographed by myself in Antikensammlung München.", by Unknown artistUnknown artist, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Glass blowing: "A Roman hydria.", licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Glass mirror: "Roman; Mirror with frame; Miscellaneous-Lead", licensed under CC0, via Wikimedia Commons. View source. View in tree.
• Glass-ceramic: "Corningware casserole dishes.", by User:Splarka, 2005, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Glider: "Glider from 1852 by George Cayley, british aviator (1774 - 1857).", by George Cayley (1774 - 1857), 1852, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Globe: "Globe according to Crates of Mallus (ca. 150 B.C.)", by Own work, adapted from original by Edward Luther Stevenson, 1921, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• GLP-1 receptor agonist: "Single conformer of exenatide peptide solved by nuclear magnetic resonance spectroscopy. 𝛼-helical secondary structure is highlighted orange. (PDB: 7MLL)", by Deposition authors: Mishra, S.H., Bhavaraju, S.; Visualization author: Synpath, 2024, licensed under CC0, via Wikimedia Commons. View source. View in tree.
• Glucose (isolation): "Structure of alpha-D-glucopyranose (Haworth projection).", by NEUROtiker, 2007, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Glucose meter: "Cover of the Preventing Chronic Diseases journal, showing a person measuring their blood sugar using a lancet and a glucose meter.", by CDC, 2013, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Glue: "Liquid w:Animal glue", by Simon Eugster – Simon / ?! 15:03, 10 May 2008 (UTC), 2008, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Glutamic acid: "Sample of L-Glutamic acid", by LHcheM, 2015, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Gold: "Synthetic made gold crystals by the chemical transport reaction in chlorine gas. Purity >99.99%", by Alchemist-hp (talk) www.pse-mendelejew.de, 2009, licensed under CC BY-SA 3.0 de, via Wikimedia Commons. View source. View in tree.
• Gold cyanidation: "Cyanide leaching "heap" at a gold mining operation near Elko, Nevada.", by see Source., 1992, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Golden rice: "Golden Rice grain compared to white rice grain in screenhouse of Golden Rice plants.", by International Rice Research Institute (IRRI), 2011, licensed under CC BY 2.0, via Wikimedia Commons. View source. View in tree.
• Golgi's method: "Photo by Bob Jacobs, Laboratory of Quantitative Neuromorphology Department of Psychology Colorado College https://www.coloradocollege.edu/basics/contact/directory/people/jacobs_bob.html", by The original uploader was Cahass at English Wikipedia., 2006, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Grafting: "Description = Zweijährige Geißfußveredelung Source = photo taken by Kobako Date = Dec. 2005 Author = Kobako", by No machine-readable author provided. Kobako assumed (based on copyright claims)., 2005, licensed under CC BY-SA 2.5, via Wikimedia Commons. View source. View in tree.
• Grain cradle: "„Ernteabend“, Holzschnitt nach einem Gemälde von Ernst Henseler, 28 x 19 cm, Verlag von Franz Hanfstängl, München. – Abgebildet ist u.a. ein Schnitter mit Reff-Sense.", by Ernst Henseler, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Grain elevator: "Drawing of the original Dart Elevator", by Unknown (published by Buffalo Courier), 1917, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Graphene: "The ideal crystalline structure of graphene is a hexagonal grid.", by AlexanderAlUS, 2010, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Graphical user interface: "A Qt application using the Keramik skin. Screenshot taken in qtconfig-qt3. Original file: https://commons.wikimedia.org/wiki/File:Qtskins.png", by The original uploader was Sikon at English Wikipedia., 2023, licensed under GPL, via Wikimedia Commons. View source. View in tree.
• Graphophone: "A Columbia type AT Graphophone, shown in a 1901 catalog published by the Maison de la Bonne Presse. Price: 110 Fr.", by Catalog published by the Maison de la Bonne Presse., 1901, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Greek fire: "Image from an illuminated manuscript, the Madrid Skylitzes, showing Greek fire in use against the fleet of the rebel Thomas the Slav.", by Unknown authorUnknown author, 1150, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Green fluorescent protein: "Aequorea victoria", by Ssblakely, 2008, licensed under Attribution, via Wikimedia Commons. View source. View in tree.
• Green fluorescent protein imaging: "Green fluorescent protein image of the mouse cochlea", by Atwiki111, 2020, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Greenhouse: "Conservatory No 28 of Botanical_Garden__V.L._Komarov_Botanical_Institute", by User:Владимир Иванов, 2006, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Greenhouse effect: "Image and caption from Popular Mechanics magazine (March, 1912) succinctly describing how burning coal causes what is now known as the greenhouse effect, and how it may affect future climate. Source: Popular Mechanics, March 1912, p. 341. Google books link: https://books.google.com/books?id=Tt4DAAAAMBAJ&pg=PA341&dq=carbon+climate&hl=en&sa=X&ved=0ahUKEwjIh86QkODcAhXCxFkKHWGpDDoQ6AEIKTAA#v=onepage&q=carbon%20climate&f=false Archive.org link: https://archive.org/details/PopularMechanics1912/Popular_Mechanics_03_1912/page/n87/mode/2up See also: https://climatebrad.medium.com/climate-hearings-af27a3886a43 (attempted archive) — informal source for other historical articles", by Writers for Popular Mechanics magazine, March 1912., 1912, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Gregorian calendar: "El LUNARIO. El "Lunario" del Vaticano y la información acerca de la reforma del Calendario Juliano por orden del Papa Gregorio XIII. Del "Lunario" de Octubre, Noviembre y Diciembre del año 1582. Notar como "salta" del 4 de Octubre al 15 de Octubre, y esto para "acomodar" nuevamente el 21 de Marzo con el Equinoccio correspondiente. Presentado a las autoridades vaticanas por Antonio Lilio, hermano de Luigi Lilio (el que hizo los cálculos) e Impreso por Vincentio Accolti. Ver transcripción del texto de la bula papal Ver cálculo del año bisiesto y reforma gragoriana Ver Correspondencia del Calendario Gregoriano con el Juliano.", by Aloysius Lilius, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Grenade: "Ceramic grenades "tetsuhau" found in a Mongolian shipwreck sunk off the Japanese Takashima Island in 1274. The ship was part of the armada of Kublai Khan attempting to conquer Japan. Balanidae (Crustacea: Cirripedia) and lower side valve specimens of Chamidae (Bivalvia) colonized the surface of the objects.", by 震天動地, 2012, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Gristmill: "Museum of Ancient Arles, Arles, France: Modell der Wassermühlen von Barbegal", by Carole Raddato from FRANKFURT, Germany, 2014, licensed under CC BY-SA 2.0, via Wikimedia Commons. View source. View in tree.
• Ground stone: "Néolithique 0001.jpg", licensed under CC BY-SA 2.5, via Wikimedia Commons. View source. View in tree.
• Guncotton: "Nitrocellulose hexanitrate.jpg", licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Gunpowder: "Black Powder in a Glass Jar (Moscow, Russia)", by Lord Mountbatten, 2012, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Gunpowder piston engine: "Huyghens' Engine, published in 1682 by Hautefeuille, referring to an experiment which had been made at the Royal Academy for raising solid bodies by means of gunpowder. He gives a description of the above apparatus, and states that he was assured that a dram of gunpowder, in a cylinder seven or eight feet high and fifteen or eighteen inches in diameter, and raised into the air seven or eight boys who held the end of the rope; and that it had in like manner raised from 1,000 to 1,200 pounds' weight.", by Jean de Hautefeuille (1647-1724) in Hautefeuille, Jean de (1682) Reflexions sur quelques machines a élever les eaux, avec la description d'une nouvelle pompe, sans frotement & sans piston, & le moyen de faire des jets d'eau de la derniere hauteur, sans avoir besoin de reservoirs élevez. A son altesse madame la duchesse de Boüillon, p. 9, 1682, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Gutta-percha (modern use): "Guttaperchabaum. A Blühender Zweig, 1/2 nat. Grösse, nach dem Original aus dem Kulturgarten in Tijkeumeuk auf Java; getrocknete Pflanze des Herbar Schiffner. — B nicht blühender Zweig, 1/2 nat. Grösse. 1 Knospe 2/1; 2 geöffnete Blüte 2/1; 3 Korolle von aussen 3/2; 4 aufgeschnittene Korolle 3/2; 5 Staubgefäss mehrfach vergr.; 6 Ovar und Griffel, mehrfach vergr.; 7 unreife Frucht; 8 dieselbe im Querschnitt; 9 reife Frucht 1/1; 10 Samen von der Seite 1/1; 11 Samen von hinten gesehen 1/1.", by Franz Eugen Köhler, Köhler's Medizinal-Pflanzen, 1897, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Gyrocompass: "Kreiselkompass der Fa. Anschütz im Schnitt", by Stahlkocher, 2005, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Gyroscope: "Gyroscope invented by Léon Foucault, and built by Dumoulin-Froment, 1852. Photo taken at the National Conservatory of Arts and Crafts museum, Paris.", by Stéphane Magnenat, 2008, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Haber process: "First ammonia reactor (9,000 tpy) from BASF during assembly at the factory Oppau", by BASF Corporate History, 1920, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Hafted axe: "Old trade axe; wood, iron; small hand axe with wooden handle attached to iron head; white circle on blade", 1918, licensed under CC BY 4.0, via Wikimedia Commons. View source. View in tree.
• Hafted spear: "Hunting spear and knife, from Mesa Verde National Park.", by Unknown authorUnknown author, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Hafting: "Title: Bulletin of the Essex Institute Identifier: bulletinofessexv15v16esse (find matches) Year: 1869 (1860s) Authors: Essex Institute. 1n Subjects: Essex Institute; Natural history; genealogy Publisher: Salem, Mass. , Essex Institute Contributing Library: Allen County Public Library Genealogy Center Digitizing Sponsor: Internet Archive View Book Page: Book Viewer About This Book: Catalog Entry View All Images: All Images From Book Click here to view book online to see this illustration in context in a browseable online version of this book. Text Appearing Before Image: ' Text Appearing After Image: ' Note About Images Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original work.", by Essex Institute. 1n, 1869, licensed under No restrictions, via Wikimedia Commons. View source. View in tree.
• Hair dryer: "From 1900 Encyclopedie Larousse Illustree.", 1900, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Half-track: "«Руссо-балт» «C24-40» из гаража Его Императорского Величества с полугусенечным приводом конструкции Адольфа Кегресса (начальника гаража и личного водителя Николая II)", by Unknown authorUnknown author, 1910, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Hall–Héroult process: "Author: user: kashkhan hall-heroult cell aluminium industrial electrolysis process for primary production diagram", by Kashkhan at English Wikipedia, 2008, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Halogen lamp: "Halogen lamp under operation", by CoolKoon, 2008, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Hampson–Linde air liquefaction: "Linde cycle 1895 -1903 patent cryo.jpg", by US uspto.gov, 1895, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Han purple and Han blue: "Detail of a mural from an Eastern Han tomb at Zhucun 朱村, Luoyang 洛陽, Henan province. The two figures in the foreground are playing Liubo, with the playing mat between them, and the Liubo board to the side of the mat. The two red, circular objects next to the liubo board are probably intended to represent lacquer wine cups. The player on the right is taking his turn, with his right hand raised up as if about to throw down the six throwing sticks. The mural is coloured using "Han Blue" and "Han Purple" pigments.", by Unknown authorUnknown author, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Hand plane: "Roman planes of 1st to 3rd century AD on display at Saalburgmuseum. Found at the roman military castel en:Saalburg Germany,. Two planes in light coloured wood are modern reconstructions.", by User:Bullenwächter, 2009, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Hand-drawn animated film: "Fantasmagorie, by Émile Cohl.", by Émile Cohl, 1908, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Handheld electronic game: "A good source of information on vintage handheld electronic games is the Electronic Handheld Game Museum (Handheldmuseum.com).", by Flickr: Joe Haupt from St. Paul, Minnesota, 2014, licensed under CC BY-SA 2.0, via Wikimedia Commons. View source. View in tree.
• Handheld film camera: "Aeroskop revolution in cinematography 1913.", by Kazimierz Prószyński (1875-1945), 2014, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Handheld game console: "The back of the Milton Bradley Microvision, the first handheld gaming console released in 1979. Built around a 16x16 LCD screen, a grid of touch controls and a paddle, the Microvision could play very simple games. These games came on interchangeable face plates that stored the main processor and custom overlays. The system's limitations lead to little support after the initial launch, and the Microvision was discontinued by 1981.", by Evan-Amos, 2017, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Handheld hair dryer: "Haartrockner AEG Modell Nr. 72355, ca. 1930er Jahre", by Phrontis, 2010, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Hang: "Front row: Ghatam (right) and the first idea of the Hang from November 1999 (left); second row: first generation Hang built 2005 (right), second generation Hang built 2006 (middle), second generation Hang built 2007 (left)", by Michael Paschko www.hangblog.org, 2007, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Hard disk drive: "Hard disk of a RAMAC 305 (1956)", by Deep silence (Mikaël Restoux), 2007, licensed under CC BY 2.5, via Wikimedia Commons. View source. View in tree.
• Hardware security module: "A nCipher nShield F3 hardware security module (HSM)", by Alexander Klink, 2008, licensed under CC BY 3.0, via Wikimedia Commons. View source. View in tree.
• Harmonica: "Comparison between 16-hole chromatic and 10-hole diatonic.", by George Leung, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Harpoon: "Multiple view of bone Azilian harpoon head, from about 10,000 years ago", by Didier Descouens, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Harpsichord: "Harpsichord in the Flemish style with the inscription SINE SCIENTIA ARS NIHIL EST (Latin "without knowledge, skill is nothing") and DUM VIXI TACUI MORTUA DULCE CANO (Latin "while I lived, I was mute, dead, I sweetly sing").", by Ratigan (instrument et photo), 2004, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Heat pump: "Piston compressor, which was installed 1878 in the salt mine of Bex, Switzerland. 1943 it was still in operation.", by Unknown authorUnknown author, 1943, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Heated greenhouse: "Conservatory No 28 of Botanical_Garden__V.L._Komarov_Botanical_Institute", by User:Владимир Иванов, 2006, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Heavy arquebus: "Original image description from the Deutsche FotothekKriegskunde & Militär & Waffe & Drill & Kavallerie & Muskete", 1664, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Helical scan: "The rotating portion of a 6 channel rotary transformer used in a six-head ("4 head" Hi-Fi NTSC VHS) VCR, showing three of the six heads on the head drum.", by No machine-readable author provided. Atlant assumed (based on copyright claims)., 2006, licensed under CC BY 2.5, via Wikimedia Commons. View source. View in tree.
• Helicopter: "Hanna Reitsch fliegt mit der Fw 61 V2", licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Helicopter drone: "A QH-50 conducts flight tests off the USS Nicholas", by U.S. Navy, 1967, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Heliograph: "heliograph - Signaling with heliograph near Monument 92. Alaska - Canada border. International Boundary Commission", by derivative work: Macchess (talk) Heliograph.jpg: US National Oceanic and Atmospheric Administration, 2008, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Heliography: "The oldest heliographic engraving known in the world. It is a reproduction of a 17th century Flemish engraving, showing a man leading a horse. It was made by the French inventor Nicéphore Niépce in 1825, with an heliography technical process. The Bibliothèque nationale de France bought it for €450,000 in 2002, deeming it as a "national treasure".", by Nicéphore Niépce (1765-1833), 1825, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Heliotrope: "Diagram of heliotrope invented by Gauss.", by Screen clipping and image cleanup by Waldir, 2008, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Helium (discovery): "Spectrum of helium (visible part)", by NASA, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Helium (isolation): "Spectrum = gas discharge tube: the noble gas: helium He. Used with 1,8kV, 18mA, 35kHz. ≈8" length.", by Alchemist-hp (talk) (www.pse-mendelejew.de), 2006, licensed under GFDL 1.2, via Wikimedia Commons. View source. View in tree.
• Heterodyne: "A heterodyne radio receiver circuit, invented in 1901 by Canadian engineer Reginald Fessenden to receive continuous wave (CW) radiotelegraphy transmissions. This was the first use of the "heterodyne" principle which Fessenden discovered. The CW radiotelegraph signal from the antenna consisted of pulses ("dots" and "dashes") of carrier wave at a radio frequency fC, which spelled out text messages in Morse code. The problem was that since the carrier had no modulation, it simply sounded like silence in the earphones of an ordinary receiver. In the heterodyne receiver, an electronic oscillator generates an unmodulated sine wave signal at a frequency fO offset from the carrier, which is added to the incoming signal from the tuned circuit. These two frequencies mix in the nonlinear crystal detector, generating a heterodyne (beat) frequency at the difference between these frequencies: fH = fC − fO whenever the carrier is present. If the local oscillator frequency is chosen correctly this heterodyne frequency will be in the audio range. Therefore the "dots" and "dashes" of Morse code will be audible as musical "beeps" in the earphones. When Fessenden invented it, there was no practical source of continuous RF sine waves to use for the oscillator. Fessenden used his enormous prototype radio alternator, but this wasn't practical. The heterodyne receiver remained a laboratory curiosity until 1913, when a cheap compact source of sine waves came along, the triode vacuum tube feedback oscillator invented by Edwin Armstrong, after which it became the standard way of receiving CW radiotelegraphy signals. Fessenden's heterodyne oscillator is the ancestor of the beat frequency oscillator used in modern superheterodyne receivers to receive CW signals. Alterations to image: changed "alternator" schematic symbol in original image to general AC source symbol, added labels", by Henri Lauer and Harry Leonard Brown, 1920, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Hidden Markov model: "hmm sequence production", by Hakeem.gadi, 2008, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Higgs boson: "An example of simulated data modeled for the CMS particle detector on the Large Hadron Collider (LHC) at CERN. Here, following a collision of two protons, a Higgs boson is produced which decays into two jets of hadrons and two electrons. The lines represent the possible paths of particles produced by the proton-proton collision in the detector while the energy these particles deposit is shown in blue. More CMS events at CMS Media", by Lucas Taylor / CERN, 1997, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• High-electron-mobility transistor: "Scheme of the High Electron Mobility Transistor (HEMT).", by Sfu, 2009, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• High-level programming language: "Cover of The Fortran Automatic Coding System for the IBM 704 EDPM, said to be the first book about Fortran.", by original uploader was en:User:Muhandis, 1956, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• High-pressure sodium-vapor lamp: "A high pressure sodium street light in Toronto", by Xiaopihar, 2020, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• High-pressure steam engine: "Richard Trevithick's high-pressure steam engine, from Scientific American Supplement, Vol. XIX, No. 470, Jan. 3, 1885 found as Project Gutenberg eText 14041 at http://www.gutenberg.net/etext/14041 NOTE: This engine is now at the Science Museum, London. Pictures may be found here.These clearly show that the nameplate says "Hazledine", not "Hazeldine".This mis-type in the Scientific American may be responsible for the number of mis-spellings present in many other sources! The text of the (public domain) article is reprinted below: TREVITHICK'S ENGINE AT CREWE. The old high-pressure engine of Richard Trevithick, which, thanks to Mr. Webb, has been rescued from a scrap heap in South Wales, and re-erected at the Crewe Works. We give engravings of this engine, which have been prepared from photographs kindly furnished to us by Mr. Webb, and which will clearly show its design. TREVITHICK'S HIGH PRESSURE ENGINE AT CREWE. TREVITHICK'S HIGH PRESSURE ENGINE AT CREWE. The boiler bears a name-plate with the words "No. 14, Hazeldine and Co., Bridgnorth," and it is evidently one of the patterns which Trevithick was having made by Hazeldine and Co., about the year 1804. The shell of the boiler is of cast iron, and the cylinder, which is vertical, is cast in one with it, the back end of the boiler and the barrel being in one piece as shown. At the front end the barrel has a flange by means of which it is bolted to the front plate, the plate having attached to it the furnace and return flue, which are of wrought iron. The front plate has also cast on it a manhole mouthpiece to which the manhole cover is bolted. In the case of the engine at Crewe, the chimney, firehole door, and front of flue had to be renewed by Mr. Webb, these parts having been broken up before the engine came into his possession. The piston rod is attached to a long cast-iron crosshead, from which two bent connecting rods extend downward, the one to a crank, and the other to a crank-pin inserted in the flywheel. The connecting-rods now on this engine were supplied by Mr. Webb, the original ones—which they have been made to resemble as closely as possible—having been broken up. In the Crewe engine as it now exists it is not quite clear how the power was taken off from the crankshaft, but from the particulars of similar engines recorded in the "Life of Richard Trevithick," it appears that a small spur pinion was in some cases fixed on the crankshaft, and in others a spurwheel, with a crank-pin inserted in it, took the place of the crank at the end of the shaft opposite to that carrying the flywheel. In the Crewe engine the flywheel, it will be noticed, is provided with a balanceweight. The admission of the steam to and its release from the cylinder is effected by a four-way cock provided with a lever, which is actuated by a tappet rod attached to the crosshead, as seen on the back view of the engine. To the crosshead is also coupled a lever having its fulcrum on a bracket attached to the boiler; this lever serving to work the feed pump. Unfortunately the original pump of the Crewe engine was smashed, but Mr. Webb has fitted one up to show the arrangement. A notable feature in the engine is that it is provided with a feed heater through which the water is forced by the pump on its way to the boiler. The heater consists of a cast-iron pipe through which passes the exhaust pipe leading from the cylinder to the chimney, the water circulating through the annular space between the two pipes. Altogether the Trevithick engine at Crewe is a relic of the very highest interest, and it is most fortunate that it has come into Mr. Webb's hands and has thus been rescued from destruction. No one, bearing in mind the date at which it was built, can examine this engine without having an increased respect for the talents of Richard Trevithick, a man to whom we owe so much and whose labors have as yet met with such scant recognition.—Engineering.", by Unknown authorUnknown author, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• High-speed maglev: "A maglev train is coming out of the Pudong International Airport.", by User Alex Needham (own photography) on en.wikipedia, 2006, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• High-speed rail: "0 series shinkansen near Yurakucho Station inTokyo", by Roger Wollstadt, 1967, licensed under CC BY-SA 2.0, via Wikimedia Commons. View source. View in tree.
• High-speed steam engine: "Porter-Allen high-speed engine (New Catechism of the Steam Engine, 1904).jpg", by Andy Dingley (scanner), licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• High-speed steel: "Identifier: americanengineer80newy (find matches) Title: American engineer and railroad journal Year: 1893 (1890s) Authors: Subjects: Railroad engineering Engineering Railroads Railroad cars Publisher: New York : M.N. Forney Contributing Library: Carnegie Library of Pittsburgh Digitizing Sponsor: Lyrasis Members and Sloan Foundation View Book Page: Book Viewer About This Book: Catalog Entry View All Images: All Images From Book Click here to view book online to see this illustration in context in a browseable online version of this book. Text Appearing Before Image: It-rMJkr- impffl 5%, ; 1 ii I, 9.—IWRT OF Tool. BACK IX TOPEKA STOREHOUSE CONTAININGLATHE, PLANER, AND BORING Tools FOi; SHIPMENT. belts and transmit more power. The countershafting wasspeeded up. These changes were under the direction of Mr.H. W. Jacobs and in line with those described by him in anextensive article on High-Speed Steel in Railroad Shops,page 338 of the September, 1904, issue of this journal. Thismatter of railroad shop machine tool equipment is consideredat length in the third number of a series of articles by Mr.Jacobs on Organization and Economy in the Railroad Ma-chine Shop in the November issue of The /■>■Magazine. Mr. Jacobs series of articles began in the Sep-tember issue of that magazine, and will be concluded in theJanuary issue. 458 AMERICAN ENGINEER AND RAILROAD JOURNAL. Text Appearing After Image: FIG. 17.—BOARD SHOWING TOOLS ORDERED, IN STOCK AND ONREQUISITION. FIG. 16.—TOOL HOLDERS AND TOOLS COMPARED TO SOLID TOOLS. December, 1906. AMERICAN ENGINEER AND RAILROAD JOURNAL. 459 At the same time standard shapes and standard materialfor cutting tools were selected by Mr. Jacobs to replace thelarge miscellaneous collection of cutting tools of all kinds,makes, shapes and qualities of material. At the present timepractically all the cutting tools for the system are made atthe Topeka shops. Each shop is furnished with a series ofblue prints, similar to those shown in Figs. 7 and S, showingthe various tools, and from these necessary supplies are or-dered by symbol number. Shaping and tempering the tools inaccordance with the best practice and manufacturing them inlarge quantities at the Topeka shops has not only greatlyincreased their efficiency, but has also effected a very con-siderable saving. It is, of course, impossible to go into this question in detailin this article, but a Note About Images Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original work.", by Internet Archive Book Images, 1893, licensed under No restrictions, via Wikimedia Commons. View source. View in tree.
• High-temperature superconductor: "A superconductor or a high-temperature superconducting ceramics is an alloy of oxides of yttrium, barium and copper in proportions YBa2Cu3O7-x and abbreviated as YBCO. This piece dimensions in 4x4x1 cm. On the picture you can see the crystalline structure of this ceramics.", by Maxim Bilovitskiy, 2015, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• High-vacuum tube: "Solton BV60 tube bass amplifier", by Christopher Schirner, 2008, licensed under CC BY-SA 2.0, via Wikimedia Commons. View source. View in tree.
• Hipposandal: "Photo of a hipposandal (Gallo-Roman horseshoe). On display at the Musee d'Ermont, France. Photo taken by NantonosAedui with a Canon G1 digital camera and reduced to suitable dimensions in Photoshop.", by NantonosAedui, licensed under CC BY-SA 2.5, via Wikimedia Commons. View source. View in tree.
• Hoe: "Skorpion II.", by Benutzer:Weneg, 2009, licensed under CC BY-SA 3.0 de, via Wikimedia Commons. View source. View in tree.
• Holography: "A white light "Rainbow" transmission hologram. There is no 3D illusion when the hologram is rotated through 90°, but there is the advantage that the image can be viewed without the need for a coherent light source such as a laser. The "backlighting" is provided by printing / micro embossing the hologram on a reflective film. Photographed using extension tubes. The full range of rainbow colours seen in a single view was obtained by placing the small illuminating light source (a halogen desk lamp) very close (a few centimeters) to the hologram, so that the angle of incidence of light varied significantly over the surface of the dove. The interference pattern needed for the dove hologram must be recorded at a resolution of approximately 1,400 fringes per mm / 35,000 fringes per inch, making holograms difficult to forge. As an additional security measure (one of very many), more than one (subtly different) version of the hologram is in use. Which one is used where? Ahhh. Now that's a secret...", by Dominic Alves, 2011, licensed under CC BY 2.0, via Wikimedia Commons. View source. View in tree.
• Home computer: "The three computers referred to by Byte Magazine as the "1977 Trinity": Commodore PET 2001, Apple II, TRS-80 Model I. (Image courtesy of Boston-based collector Timothy Colegrove. For more information about this image send an email to timothy.colegrove@gmail.com)", by Trinity77.jpg: Tim Colegrove derivative work: Pittigrilli, 2019, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Home pregnancy test: "Patent for first home pregnancy test by Margaret Crane", by Margaret Crane, 1969, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Hook-and-loop fastener: "Hook and loop fastener - macro photograph of "hooks"", by Kamranki, 2015, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Horizontal pendulum seismograph: "Exhibit in the National Museum of Nature and Science, Tokyo, Japan. Photography was permitted in the museum without restriction.", by Daderot, 2013, licensed under CC0, via Wikimedia Commons. View source. View in tree.
• Horse collar: "Earliest equine harness 477 499 cave 257", by Unknown authorUnknown author, 2020, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Horse-drawn seed drill: "Seed drill", by Jethro Tull, 1731, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Horse-drawn tram: "Horse-powered train on the en:Swansea and Mumbles Railway, Wales", by Unknown authorUnknown author, 1865, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Horsepower: "Illustration of the original definition of "Horsepower" as coined by James Watt in the late 18th century.", by User:Sgbeer; adapted by User:Martinvl, 2017, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Hot blast: "A Set of Modern Blast Furnaces Shown in Section In the centre background is the stove for heating the blast. Note the passage-way at top leading from one furnace to the other and to the stove.", by Andy Dingley (scanner), 1931, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Hourglass: "allegory of good government", by Ambrogio Lorenzetti, 1338, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Hovercraft: "Tunisee Freiburg im Breisgau, Formel 1 Hovercraft Rennboot", by Thomas Philipp, 2007, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Howitzer: "SC369397 - KOREAN CONFLICT A gun crew from Company "A", 90th Field Artillery Battalion, 24th U.S. Infantry Division, fires a 155-mm howitzer at Communist positions in the Kojongchon sector, eight miles above the 38th Parallel. 3 June 1951. Korea. Signal Corps Photo #8A/FEC-51-18646 (Hildreth)", licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Human genome sequencing: "Human Genome Project logo (color).", by U.S. Department of Energy, Human Genome Project, 2006, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Human in vitro fertilisation: "The process of IVF explained step by step - English", by https://zealthy.in/en, 2020, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Hurdy-gurdy: "Louvet Drehleier.JPG", licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Hwacha: "The back view of a Hwacha battery.", by draq, 2006, licensed under CC BY 2.0, via Wikimedia Commons. View source. View in tree.
• Hybrid electric car: "picture of company "Jacob Lohner & Co"", by Unknown authorUnknown author, 1902, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Hybrid integrated circuit: "Replica of first integrated circuit by Jack Kilby. Nixdorf-Museum", by Florian Schäffer, 2015, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Hydraulic accumulator: "Grimsby Dock Tower Grimsby Dock Tower stands 300 feet high and was built in 1851, originally to provide high pressure water to hydraulic machinery around the lock gates of Grimsby Fish Dock. It is a Grade 1 listed building. Location 53°34'58.25"N, 0° 4'13.68"W For more information on the tower see Link", by Colin Westley (Uploaded by User:PeterJewell), 1999, licensed under CC BY-SA 2.0, via Wikimedia Commons. View source. View in tree.
• Hydraulic excavator: "HY-MAC 1501 Excavator, British Design.", by Digger tom, 2013, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Hydraulic power network: "Hydraulic pumping station, Underfall Yard, Bristol Docks; Power for sluices and lock gates etc was provided by water under pressure from this pumping station.", by Chris Allen, 1988, licensed under CC BY-SA 2.0, via Wikimedia Commons. View source. View in tree.
• Hydraulic press: "Hydraulics: section and details of the Bramah hydrostatic press. Engraving by Lowry after J. Farey. Iconographic Collections Keywords: John Farey; Joseph Bramah; Lowry", licensed under CC BY 4.0, via Wikimedia Commons. View source. View in tree.
• Hydraulic telegraph: "A relief of the Greek hydraulic telegraph of Aeneas, depicting one half of a telegraph system. The soldier holding the raised torch is watching the descent of a floating message indicator stick (which is marked with message codes) as water is released from the reservoir chamber the stick is floating in. When the float indicator reaches the appropriate level (corresponding to a certain predetermined message), the soldier's flame will be hidden or extinguished. On the distant hill shown near the top left of the relief, an observer with an identical hydraulic chamber is observing the flame, and waiting for it to be extinguished, at which time that reservoir spout will be closed and the message read from the identical floating message indicator stick.", by Original relief: unknown; modern photograph of the relief contributed by Demetre Valaris via his website (no copyright applies), licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Hydroelectric power plant: "Photochrom print of industrial plants along the Niagara River, approximately ½ mile down river of the American Falls.[1]", by Detroit Publishing Co., 1900, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Hydroelectricity: "Burnfoot Power House. Generator, turbine, etc, Cragside Estate, Rothbury, England.", by Rosser1954, 2016, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Hydrogen: "Scan of a drawing of Cavendish's apparatus for making hydrogen gas", by Henry Cavendish, 1766, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Hydrogen balloon: "N°. 5 – Premier voyage aérien par Charles et Robert (1783) First aerial voyage by Charles and Robert · Erste Flugreise mit Charles und Robert", by Created/published: Paris : Romanet & Cie., imp. edit.,, 1890, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Hydrogen bomb: "Castle Romeo nuclear test (yield 11 Mt) on Bikini Atoll. It was the first nuclear test conducted on a barge. The barge was located in the Castle Bravo crater.", by United States Department of Energy, 1954, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Hygrometer: "Hair tension hygrometer. Made in East Germany", by Daniel FR at de.wikipedia.org, 2004, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Hypermedia: "The Quick and Dirty Animation System developed at the Architecture Machine Group in 1979 in conjunction with the Aspen Movie Map project. This figure shows the texture-mapping feature.", by Walter.bender, 1979, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Hypertext Transfer Protocol: "HTTP logo as used by the IETF HTTP Working Group (HTTPbis)", by IETF HTTP Working Group (HTTPbis), 2014, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Hypocaust: "Pilettes et praefurnium de la maison au grand péristyle de Vieux-la-Romaine (Calvados, Normandie, France).", by Pascal RADIGUE, 2015, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Hypodermic needle: "Illustration of Francis Rynd's hypodermic syringe and trocar.", by Hodges and Smith, 1846, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• I-beam: "w:en:I-beam used for the load-bearing structure of a house.", by Todd Murray, 2006, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Ibuprofen: "Ball-and-stick model of the (R)-ibuprofen molecule, based on neutron diffraction data from N. Shankland, C. C. Wilson, A. J. Florence and P. J. Cox (1997). "Refinement of Ibuprofen at 100K by Single-Crystal Pulsed Neutron Diffraction". Acta Crystallographica Section C 53: 951-954. DOI:10.1107/S0108270197003193.", by Ben Mills, 2008, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Ice-making machine: "1 of 3: Icemaker patent by Andrew Muhl, 1871", by Matthew.muhl, 2016, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Ignition magneto: "The magneto is an engine-driven alternating current (AC) generator. At first, the magneto generates electrical power by the engine rotating the permanent magnet and inducing a current to flow in the coil windings. As current flows through the coil windings, it generates its own magnetic field that surrounds the coil windings, until the current flow is stopped, and the magnetic field collapses across a second set of windings in the coil, causing a high-voltage to arc across the spark plug gap.", by U.S. Department of Transportation FEDERAL AVIATION ADMINISTRATION Flight Standards Service, 2018, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Implantable cardioverter-defibrillator: "Implantable cardioverter-defibrillator", by n28ive1 on Flickr, 2007, licensed under CC BY 2.0, via Wikimedia Commons. View source. View in tree.
• Implantable pacemaker: "Foto des implantierbaren Herzschrittmachers", by Msenning, 1958, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Impulse generator: "Jedlik Ányos csöves villámfeszítője", by The original uploader was Tambo at Hungarian Wikipedia., 2011, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• In vitro fertilisation: "Intracytoplasmic Sperm Injection Image", by US Government Owned Photo, 2016, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• In-ovo sexing: "Chick.jpg", licensed under GFDL 1.2, via Wikimedia Commons. View source. View in tree.
• Incense: "Shanghai, Longhua Temple incense", by Photo by NosniboR80, CC License, licensed under CC BY-SA 2.5, via Wikimedia Commons. View source. View in tree.
• Incense clock: "IncenseAlarmClock.JPG", licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Indigo dye: "Extract of Indigo plant applied to paper", by prepared by Palladian, 2004, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Induced pluripotent stem cell: "Researchers at NIH's National Eye Institute (NEI) developed the first patient-derived stem cell model for studying eye conditions related to oculocutaneous albinism (OCA). Learn more: at https://www.nih.gov/news-events/news-releases/nih-researchers-develop-first-stem-cell-model-albinism-study-related-eye-conditions In this image: A human induced pluripotent stem cell colony from OCA1A patient. The image was acquired using a confocal microscope and is stained for pluripotency marker proteins. The red color depicts transcription factor OCT4, green is SSEA4 protein and blue represents the nucleus of the cells. Credit: National Eye Institute/NIH", by NIH Image Gallery from Bethesda, Maryland, USA, 2022, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Induced radioactivity: "Irène and Frédéric Joliot-Curie in their laboratory in 1935.", by Agence de presse Meurisse, 1935, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Induction coil: "Induction coil (also called "spark coil" or "Rühmkorff coil"), used in science education probably around 1900, on display in the Schulhistorische Sammlung (School Historical Museum), Bremerhaven, Germany. It generates high voltage from low voltage direct current (D). Inside the cylinder is the primary winding, consisting of relatively few turns of thick wire, wrapped around an iron core. It can be seen sticking out of both ends of the coil. Around this is wound the secondary winding, consisting of many turns of fine wire. At the left end of the core is a vibrating contact called an "interrupter", which repeatedly breaks the current in the primary circuit to provide the flux changes necessary for induction. When operating, the high voltage from the secondary is applied to the spark gap at the top, creating a stream of sparks", by Hannes Grobe (talk), 2008, licensed under CC BY 3.0, via Wikimedia Commons. View source. View in tree.
• Induction motor: "Model of induction motor with short circuit rotor. Nikola Tesla Museum, Belgrade, Serbia", by Ctac, 2012, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Inductive charging: "Diagram of inductive charging.", by Egmason, 2010, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Influence machine: "Drawing of electrophorus electrostatic generator, invented by Johan Carl Wilcke in 1764, from an 1840 chemistry text. It consists of a 'cake' of dielectric resinous material like wax, at bottom, and a metal plate on an insulated handle that can be placed on it. After charging the bottom plate by rubbing with fur, the top plate could be repeatedly charged by placing it on the surface and grounding the top by touching the small ball, then removing it. Alterations: removed caption and part labels, increased brightness.", by Robert Hare, 1840, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Information theory: "Information entropy (in bits) is the log-base-2 of the number of possible outcomes. With two coins there are four outcomes HH-HT-TH-TT, and the entropy is two bits.", by http://www.cngcoins.com/, 2013, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Infrared LED: "A 1963 Texas Instruments SNX-110 GaAs IR LED with dome-shaped GaAs diode.", by James R. Biard, 1963, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Injection molding: "Injection molding - simplified diagram", by ariel cornejo, 2015, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Ink: "Black Waterman ink bottle.", by Eric Magnan, 2014, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Inkjet printing: "A Canon PIXMA TS207 printer idling, after it printed a print head alignment pattern.", by Paowee, 2024, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Insulated-gate bipolar transistor: "IGBT 3300V/1200A - Mitsubishi reference CM1200HC-66H", by User:ArséniureDeGallium (2005), 2005, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Insulin: "Insulin consists of two peptide chains, linked with two disulphide bridges shown in yellow (the third disulfide bridge has no role in the linkage)", by User:AtikaAtikawa, 2021, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Insulin pump: "A picture I took of my Minimed Medtronic Paradigm 512 insulin pump, showing an infusion set attached to a reservoir. The blue object is a spring-loaded insertion device to insert the metal needle (which is surrounded by a plastic cannula) beneath the skin. The metal needle is then removed, leaving the cannula in place.", by User:David-i98 at en.Wikipedia, 2007, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Integrated cartridge: "Breech-loading shotgun using self-contained cartridges, from the French patent taken out 29 September 1812 by Samuel Johannes Pauli.", by Unknown authorUnknown author; invented by Samuel Johannes Pauli, 1812, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Integrated circuit computer: "Scientific Data Systems model 930 at Swissair", by Swissair, 1966, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Intercontinental ballistic missile: "stamp from mini-sheet. Country name in Abkhaz", by Post of Abkhazia, 2008, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Intermodal container: "Red Shipping container of Lorenzo Shipping Corporation", by KMJ at German Wikipedia, 2004, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Internal combustion engine: "Lenoir engine", by Johannes Maximilian, 2017, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• International system of units: "Illustration of the SI system of units, with base units and defining constants used to define them: s - the frequency of the caesium transition for the second, kg - the mass of the IPK for the kilogram, mol - the mass in kilograms of an atom of carbon 12 for the mole, cd - the sensitivity of the human eye for the candela, K - the Boltzmann constant for the kelvin, A - the magnetic permeability of vacuum for the ampere, m - the speed of light for the metre.", by BIPM, 2017, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Internet forum: "The screenshot of phpBB 3.0.", by Meow, 2007, licensed under GPL, via Wikimedia Commons. View source. View in tree.
• Internet protocol suite: "SRI’s role in the first internetworked connection (diagram)", by SRI International, 1977, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Iodine: "Evaporating pure iodine.", by Jurii, 2009, licensed under CC BY 3.0, via Wikimedia Commons. View source. View in tree.
• Iron: "A 500g endcut from the Toluca iron meteorite (coarse octahedrite, class IA). Shown here is the cut, polished and etched face, displaying Widmanstätten Pattern.", by H. Raab (User:Vesta), 2005, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Iron lung: "This photograph shows an opened artificial respirator commonly known as the iron lung. Polio patients of the 1950s depended on these devices to breathe after being paralyzed with this devastating virus. This iron lung was donated to the CDC’s Global Health Odyssey by the family of polio patient Mr. Barton Hebert of Covington, Louisiana, who’d used the device from the late 1950s until his death in 2003.", by Photo Credit: Content Providers(s): CDC/GHO/Mary Hilpertshauser, 2004, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Iron smelting and wrought iron: "Bronze Razor from the Hallstatt culture. Musée de l'Ardenne, France. The handle is fixed and the razor has two cutting edges. Decorative ridges can also be seen following the direction of the handle into the blade. The pointed tip of the blade indicates additional uses as a knife or a weapon. The three circular holes on the handle and the blade body indicate the possibility they could be used for fasteners in a spear head as well. It is on exhibit at the Ardennes Museum in France.", by Vassil, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Ironclad: "LaGloirePhotograph.jpg", licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Irrigation: "Water flows through an irrigation canal near Fira Shia, Iraq that once had barely enough water for farmers to use for subsistence farming.", by Christopher Ellis, U.S. Army, 2007, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Isotopes: "In the lower right corner of the photographic plate are the tracks left by two isotopes of neon: neon-20 and neon-22.", by Francis William Aston, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Jacob's staff: "This file was provided to Wikimedia Commons by Museo Galileo as part of a GLAM-WIKI project with Wikimedia Italia.", by Museo Galileo, 2010, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Jacquard loom: "Jacquardmaschien für endlose Papierkarten (Verdol)", by David Monniaux, 2006, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Janssen photographic revolver: "Revolver fotografico", by Auguste Tilly, 1875, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Jet aircraft: "The Heinkel He 178, the first jet-powered aircraft.", by Unknown authorUnknown author, 1939, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Jet airliner: "G-APMA (cn 06421)", by BEA_De_Havilland_DH-106_Comet_4B_Manteufel.jpg: Ralf Manteufel derivative work: Altair78 (talk), 2012, licensed under GFDL 1.2, via Wikimedia Commons. View source. View in tree.
• Jew's harp: "陶寺文化 口弦琴 陶寺遗址出土", by Siyuwj, 2022, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• JFET: "Diagram of a Junction-Gate Field-Effect Transistor (JFET)", by Vector version: VectorVoyager PNG version: Rparle at English Wikipedia, 2023, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Joule heating: "Powered quartz element from a commercial quartz conveyor toaster", by Cyungbluth, 2015, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Joule–Thomson effect: "Throttling in the Ts diagram of nitrogen", by Adwaele, 2012, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Kaplan turbine: "A Kaplan turbine in a power plant", by uploaded by Duk, 2004, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Kelvin scale and absolute zero: "Relations among temperature scales in common use.", by MikeRun, 2019, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Kelvin water dropper: "A model of the Kelvin water dropper electrostatic machine invented by Scottish scientist William Thomson (Lord Kelvin) in 1867, on display at the SPARK Museum of Electrical Invention, Bellingham, Washington, USA. This is a fairly faithful replica of Kelvin's original machine sold for educational use in high school and college science classes by a scientific instrument company around the turn of the century.", by Chetvorno, 2018, licensed under CC0, via Wikimedia Commons. View source. View in tree.
• Kepler's laws of planetary motion: "Kepler Mars retrograde.jpg", licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Keplerian refracting telescope: "Fig. AA from Machinae coelestis, 1673, by Johannes Hevelius (1611-1687). Typ 620.73.451, Houghton Library, Harvard University", by Johannes Hevelius, 1673, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Kerosene: "Lighting kerosene in 720 ml mason jar", by Burger, 2008, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Kerosene lamp: "Канадський науковець", by Daniil Kolesnichenko, 2024, licensed under CC BY 4.0, via Wikimedia Commons. View source. View in tree.
• Kevlar: "Golden yellow aramid fiber (Kevlar). The diameter of the filaments is about 10 µm. Melting point: none (does not melt). Decomposition temperature: 500-550 °C. Decomposition temperature in air: 427-482 °C (800-900 °F).", by Cjp24, 2009, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Kiln: "Wildrose Charcoal Kilns in Death Valley, California. The ten kilns (25 feet, or 7.6 m, high) were used to make charcoal from wood to smelt lead and silver from nearby mines. Built in 1877, they were only in operation for 2 or 3 years. [1]", by Mav at English Wikipedia, 2003, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Kinetophone: "Publicity photograph of man using Edison Kinetophone, ca. 1895", by [1], 1895, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Kinetoscope: "Illustration of the rear interior of a Kinetoscope machine.", by Albert Tissandier, 1894, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Kithara: "Kithara player 445-435 BC from vase (München, Staatliche Antikensammlungen SCH 80).", by Achilles Painter - period / date: classical, ca. 445-435 BC photographed by ArchaiOptix photographer's note: Some museums permit photography of their exhibits for private, educational and scientific purposes only. If you intend to use the photo for commercial aims, I would recommend you to contact the museum., licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Knitting: "Visit of the Angel, from the right wing", by Master Bertram, 1400, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Kraft paper process: "papel para hacer milde", by Marian Gutierrez, 2016, licensed under CC0, via Wikimedia Commons. View source. View in tree.
• Krypton: "Spectrum = gas discharge tube: the noble gas: krypton Kr. Used with 1,8kV, 18mA, 35kHz. ≈8" length.", by Alchemist-hp (talk) (www.pse-mendelejew.de), 2006, licensed under GFDL 1.2, via Wikimedia Commons. View source. View in tree.
• Lacquer: "China; Dish; Lacquer", 1522, licensed under CC0, via Wikimedia Commons. View source. View in tree.
• Lambda calculus: "A term with links (version 2 without @)", by PIerre.Lescanne, 2018, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Lamellar armour: "​秦始皇兵马俑，跪射俑", by Camphora, 2008, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Laminated glass: "Windshield with "spiderweb" cracking.", by Tysto, 2005, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Lancashire loom: "Weaving shed, Queen Street Mill A typical shed. There would be 800-1200 Lancashire looms in a typical shed, each taking about 0.5 horsepower of steam engine power and producing an incredible din. The mill girls communicated by lip reading a skill called mee-mawing (somebody will correct the spelling).", by Chris Allen, 1986, licensed under CC BY-SA 2.0, via Wikimedia Commons. View source. View in tree.
• Land mine: "​火龍經 明朝 焦玉", by 焦玉, 2021, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Laptop computer: "Epson HX-20 portable computer", by Steven Stengel, 2008, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Large language model: "An illustration of multiple attention heads, each having its own criteria of relevance of other tokens for one of the tokens within the scope of a context window. (For the purpose of illustration, the context window consists of only one sentence.)", by DancingPhilosopher, 2023, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Laser: "World's first laser created by Theodore Maiman in 1960. Picture taken in 2004 by the creator and his wife in Vancouver, Alberni street.", by Theodore and Kathleen Maiman, 2004, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Laser cutting: "Bystronic Laserschneiden", by Bystronic, 2006, licensed under CC BY-SA 2.5, via Wikimedia Commons. View source. View in tree.
• Laser printer: "IBM 3800 continuous-form laser printer", by International Business Machines, General Products Division, 1982, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• LaserDisc: "12 inch LaserDisc being held by a woman, giving an idea of the size of the disc itself.", by Windell Oskay, 2013, licensed under CC BY 2.0, via Wikimedia Commons. View source. View in tree.
• Lashed-lug boat building: "Lashed-lug planking in the Butuan balangay boat Two (Clark, Vosmer, & Santiago, 1993). Based on illustration by Tom Vosmer.", by Obsidian Soul, 2021, licensed under CC0, via Wikimedia Commons. View source. View in tree.
• LASIK: "BETHESDA, Md. (May 1, 2007) - Capt. Joseph Pasternak, an ophthalmology surgeon at National Naval Medical Center Bethesda, lines up the laser on Marine Corps Lt. Col. Lawrence Ryder's eye before beginning LASIK VISX surgery. The actual procedure can take only seconds, while most of the patient's time is spent preparing for the procedure. The new VISX procedure only takes days for service member's to recover, versus months like the old PRK procedure. U.S. Navy photo by Mass Communication Specialist 1st Class Brien Aho (RELEASED)", by U.S. Navy photo by Mass Communication Specialist 1st Class Brien Aho, 2007, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Lateen and settee sail: "Meister der Predigten des Heiligen Gregor von Nazianz 001.jpg", by Meister der Predigten des Heiligen Gregor von Nazianz, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Lathe: "lathe from the tomb of Petosiris, around 300 BC", by Unknown authorUnknown author, 1923, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Latitude and longitude: "A mid-15th century Florentine map of the world based on Jacobus Angelus's 1406 Latin translation of Maximus Planudes's late-13th century rediscovered Greek manuscripts of Ptolemy's 2nd-century Geography. Ptolemy's 1st (modified conic) projection.", by Credited to Francesco di Antonio del Chierico, 1450, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Laudanum: "Some of the ingredients used in medical treatments seem to belong to the world of fantasy rather than pharmacy. On the far left is a dispensing pot labelled “LAUD:NEP:QUERC”. This is laudanum, a treatment made from opium, gold and pearls. Mixed with a powdered bezoar stone from the stomach of an animal and shavings of mythical unicorn horn, the medicine was given to aid sleep and ease pain. The jar, one of four shown here, was presented as a gift to the Wellcome collection on the previous owner’s death in 1932. maker: Unknown maker Place made: Italy Wellcome Images Keywords: laudanum; Opium; controlled drug; Pharmacy; dispensing pot; bezoar", licensed under CC BY 4.0, via Wikimedia Commons. View source. View in tree.
• Lawn mower: "A reel lawn mower, adapted from an illustration used in an advertisement in a 1888 issue of Garden and Forest. The ad was placed by Chadborn & Coldwell Manufacturing in Newburgh, New York.", by Unknown authorUnknown author (Chadborn & Coldwell Manufacturing in Newburgh, New York), 1888, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Lead chamber process: ""Apparatus for making sulfuric acid in lead compartments"", by Louis Figuier, 2010, licensed under CC BY 2.0, via Wikimedia Commons. View source. View in tree.
• Lead pipes: "Chester ( England ). Grosvenor Museums: Ancient Roman lead water pipes ( 1st century ) with inscription IMP.VESP.VIIII.T.IMP.VII.COS.CN.IULIO.AGRICOLA.LEG.AUG.PR.PR. ( (made) when the Emperor Vespasian was consul for the ninth time and the Emperor Titus was consul for the seventh time, when Gnaeus Iulius Agricola was imperial governor (of Britain)).", by Wolfgang Sauber, 2011, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Lead smelting: "Ancient Greek sling bullets with engravings. One side depicts a winged thunderbolt, and the other, the Greek inscription “take that” (ΔΕΞΑΙ) in high relief.", licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Lead–acid battery: "A 19th century illustration of Gaston Plante's original lead acid cell.", licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Leavers machine: ""Leavers's Lace Machine."", by Samuel L. Goldenberg, 1904, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Leclanché cell: "Samson Battery No. 2, a Leclanché wet cell battery manufactured by the Samson Electric Co., Canton, Massachusetts, c. 1868. National Museum of American History    Native name National Museum of American History  Parent institution Smithsonian Institution  Location Washington, D.C. , United States Coordinates 38° 53′ 28″ N, 77° 01′ 48″ W   Established January 1964  Website americanhistory.si.edu  Authority file : Q148584 VIAF: 127977835 ISNI: 0000000404805762 ULAN: 500250889 LCCN: n81015980 NLA: 36241847 WorldCat institution QS:P195,Q148584 Accession number: 249201 ID number: EM.322990 National Museum of American History record ID: nmah_1274474", by Crawdad Blues, 2024, licensed under CC0, via Wikimedia Commons. View source. View in tree.
• LED display: "Seven-segment display digits of an original Texas Instruments TI-30 scientific calculator (circa 1979).", by Loadmaster (David R. Tribble) This image was made by Loadmaster (David R. Tribble). Email the author: David R. Tribble Also see my personal gallery at Google Photos, 2012, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• LED lamp: "LED household light bulb with E27 Edison screw, with internal circuitry exposed.", by Loadmaster (David R. Tribble) This image was made by Loadmaster (David R. Tribble). Email the author: David R. Tribble Also see my personal gallery at Google Photos, 2021, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Leibniz wheel: "Title: Details of the mechanisms of the Leibniz calculator, the most advanced of its time Abstract/medium: 1 print : engraving.", by Leupold, Jacob, 1674-1727., 1727, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Lever escapement: "Ankerhemmung Phase 1", by This vector image was created with Adobe Illustrator by v., 2014, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Lever tumbler lock: "A common type of mortise lock in the UK, of the lever lock type.", by Willh26, 2016, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Leyden jar: "Artist's conception of the discovery of the Leyden jar. In 1746, Andreas Cunaeus, a pupil of Pieter von Muschenbroek in Leyden, attempts to "condense" electricity in a glass of water. The rotating glass sphere (right) is an electrostatic machine. The static electricity generated by the hands rubbing on it is transferred through the chain to the suspended metal bar, and from it via the hanging wire into the glass of water. The glass acted as a capacitor, and a large charge built up in the water, and an equal charge of the opposite polarity built up in Cunaeus' hand holding the glass. When Cunaeus reached up to pull the wire out of the water, he got a severe shock, much worse than an electrostatic machine could give, because the amount of charge stored was much larger than the terminal of an electrostatic machine could store. Cunaeus took two days to recover. Musschenbroek was also impressed by the powerful shock he received from the device, writing, "I would not take a second shock for the crown of France". Reports of the experiment were widely circulated, and scientists began to investigate the charge storage ability of these "Leyden flasks". Eventually the water was replaced by foil coatings on the inside and outside of the jar to store the charge.", by The drawing seems to be signed 'Laplante' in the lower right corner, 1886, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Library catalog: "Library cataog from gymnasion of the Hellenistic period. Found in 1969 in the cistern next to hotel the Bristol Park in Taormina. Lapidary and epigraphic collection of Greek Theatre of Taormina.", by Zde, 2014, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Lidar: "This Leica terrestrial lidar (light detection and ranging) scanner (TLS) may be used to scan buildings, rock formations, etc., to produce a 3D model. The TLS can aim its laser beam in a wide range: its head rotates horizontally, a miror flips vertically. The laser beam is used to measure the distance to the first object on its path. Model: Leica HDS-3000 The Lidar was being demonstrated at UC Santa Cruz when the photo was taken.", by David Monniaux, 2007, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Light bulb: "An original Edison light bulb from 1879 from Thomas Edison's shop in Menlo Park.", by Terren, 2008, licensed under CC BY 2.0, via Wikimedia Commons. View source. View in tree.
• Light-emitting diode: "R, G, and B LEDs", by PiccoloNamek, 2005, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Lighthouse: "Tower of Hercules, an ancient Roman lighthouse in A Coruña, northern Spain.", by Fernando, 2023, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Lightning rod: "De Blitz-Ableitung Reimarus r 46.jpg", by J. A. H. Reimarus, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Limelight: "Limelight uit 19e eeuw. Collectie Stadsschouwburg Brugge", by Beireke1, 2022, licensed under CC BY 4.0, via Wikimedia Commons. View source. View in tree.
• Line printer: "Title: New machine to speed up statistics of census of 1940. Washington, D.C., Dec. 2. Back in 1870, it took 7 years to compile statistics from the facts taken by census takers, but in the next 10 years, Herman Hollerith invented a 'unit tabulator,' shown on left of photo being operated by Operator Ann Oliver. This machine is fed cards containing census information at the rate of 400 a minute and from these, 12 separate bits of statistical information is extracted. Not so long ago, Eugene M. La Boiteaux, Census Bureau inventor, turned out a smaller, more compact machine, which extracts 58 statistics from 150 cards per minute. This machine is shown on the right and is being operated by Virginia Balinger, Assistant Supervisor of the current Inquiry Section. With the aid of this machine, statistical information from the 1940 census is expected to be compiled in 2 1/2 years. The secret of the machine lies in the cards. The written information taken by census takers is brought in and the data translated into code numbers which are punched on the card, and the legible data is locked up in vaults away from prying eyes. Cards are fed into the machine, sensitive steel fingers feel out the punches, set up electrical impulses, and in no time at all, the card has set down on the large sheet just what statistic from each individual goes in what place Abstract/medium: 1 negative : glass ; 4 x 5 in. or smaller", by Harris & Ewing, photographer, 1939, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Linear motor: "Erfordern lineare Verfahrensbewegungen ein Höchstmaß an Dynamik und Präzision, ist ein Linearmotor die ideale Lösung", by Schnibbi678, 2013, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Linen: "Linen cloth.jpg", licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Liquefied gas refrigerants: "RSS Refrigerator electronics and electronics", by N-Lange.de, 2009, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Liquid compass: "Magnetic compass.", by Chopper, 2008, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Liquid nitrogen: "Liquid nitrogen", by Cory Doctorow aka gruntzoki on Flickr, 2008, licensed under CC BY-SA 2.0, via Wikimedia Commons. View source. View in tree.
• Liquid oxygen: "Liquid oxygen", by Staff Sgt. Nika Glover, U.S. Air Force, 2010, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Liquid-crystal display: "Digital clock using Cyanobiphenyl liquid crystals made at the Royal Radar Establishment (RRE) in 1973. This is one of the first demonstration uses of Cyanobiphenyl liquid crystals discovered that year.", by Royal Radar Establishment, 1973, licensed under OGL 3, via Wikimedia Commons. View source. View in tree.
• Liquid-propellant rocket: "Dr. Robert H. Goddard and a liquid oxygen-gasoline rocket at Auburn, Massachusetts.", by Esther C. Goddard, 1926, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Lira da braccio: "detail", by Bartolomeo Montagna, 1500, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Lithium: "A freshly cut sample of lithium, with some oxides already formed", by Dnn87, 2007, licensed under CC BY 3.0, via Wikimedia Commons. View source. View in tree.
• Lithium battery pacemaker: "A medical device that generates electrical impulses delivered by electrodes to cause the heart muscle chambers (the upper, or atria and/or the lower, or ventricles) to contract and therefore pump blood; by doing so this device replaces and/or regulates the function of the electrical conduction system of the heart. Pacer designed by Anthony J. Adducci and Arthur Schwalm.", by Brian Adducci, 2021, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Lithium iodide battery: "The Central Intelligence Agency often develops technology and conducts research that not only advances its mission but, when declassified, can have significant impact on the world. In the 1970s, the CIA shared research it had done on lithium-iodine batteries with the medical community. This same technology is used in heart pacemakers today. For more information on CIA history and this artifact please visit www.cia.gov", by The Central Intelligence Agency, 2011, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Lithium-ion battery: "Nokia Li-ion Battery.", by Kristoferb, 2010, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Lithium-ion electric car: "Tesla Roadster is sold throughout North America, Europe and Asia.", by Tesla Motors Inc., 2010, licensed under Copyrighted free use, via Wikimedia Commons. View source. View in tree.
• Lithography: "Portrait of Alois Senefelder, lithograph", by Lorenzo Quaglio the Younger, 1818, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• LLM chatbot: "An example of a ChatGPT hallucination. When prompted to “summarize an article” with a fake URL that contains meaningful keywords as slug, even with no Internet connection, the chatbot generates a response that seems valid at first glance.", by ChatGPT, 2023, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Logarithm: "A page from Mirifici logarithmorum canonis descriptio by John Napier. The left-most column gives minutes to be added to the angle for this page, 34 degrees. The far right column is the co-angle (90° - x). This page covers 30 to 60 minutes; a facing page covers 0 to 30 minutes. Adjacent to each outer column is the sine of that angle, followed towards the middle by the absolute value of natural log of the sine. One can get cosines easily by reading across the page from the co-angle. In the middle column is the difference between the two logs, which is the natural log of the tangent function (cotangent if you reverse sign).[1]", by John Napier, 1614, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Long division: "Illustration of the Book "Number Stories of long ago", extracted from page 78 Oldest long division", by David Eugene Smith, 1919, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Long short-term memory: "Schematic of the Long-Short Term Memory cell, a component of recurrent neural networks", by Guillaume Chevalier, 2018, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Loom with punched tape: "Photograph of a Basile Bouchon automated loom from 1725, displayed at the Musée des arts et métiers, Paris.", by Dogcow, 2010, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Lost-wax casting: "Bronze Casting by the Lost Wax Method", by originally User:Jonkerr, redone by User:H Padleckas, 2004, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Low-pressure sodium-vapor lamp: "This image I made myself along a street in Holland. {{This image I made myself along a street in Holland.|day=16|month=December|year=2004}}", by Skatebiker at English Wikipedia, 2004, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• LSD: "10 hits of White On White (WOW) LSD.", by Coaster420, 1938, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• LTE and 4G cellular network: "HTC Thunderbolt.jpg", by Ryry17354 at English Wikipedia, 2011, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Lumière cinematograph: "Institut Lumière - CINEMATOGRAPHE Camera.", by Victorgrigas, 2014, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Lunar and lunisolar calendars: "Calendar of Coligny - detail (Lyon, Mus Gall-Rom BR 1).jpg", by Mark Landon, 2016, licensed under CC BY 4.0, via Wikimedia Commons. View source. View in tree.
• Lunar lander: "The Apollo 11 Lunar Module Eagle, in a landing configuration was photographed in lunar orbit from the Command and Service Module Columbia. Inside the module were Commander Neil A. Armstrong and Lunar Module Pilot Buzz Aldrin. The long rod-like protrusions under the landing pods are lunar surface sensing probes. Upon contact with the lunar surface, the probes sent a signal to the crew to shut down the descent engine.", by NASA, 1969, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Lute: "Egyptian lute players. Fresco found in Thebes, from the tomb of Nebamun, a nobleman in the 18th Dynasty of Ancient Egypt (c. 1350 BC).", by Unknown authorUnknown author, 1350, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Lyocell: "Ткань с волкнами Lyocell в чехле матраса.", by Dobrozhinetsky, 2011, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Lyre: "Ur lyre.jpg", licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Macuahuitl: "Aztec warriors led by an eagle knight, each holding a macuahuitl club. Copy of a painting from Florentine Codex, book IX, F, 5v.", by Unknown artist. Manuscript written by Bernardino de Sahagún, 1550, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Magdeburg hemispheres: "Otto von Guericke", by Gaspar Schott (1608 - 1666), licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Magic lantern: "caption: "Fig. 404. The Magic Lantern of Kircher. (From the Ars Lucis et Umbrae, 1671, p. 768) The lamp is a naked flame with a concave reflector behind it. The lantern slide is a long strip with many pictures which can be shown one after the other. The lantern slide appears at the wrong end of the projection objective, making it difficult to see how any image could be projected. At the bottom of the picture is a part of the text in which the better form of Walgenstens's lantern is conceded."", by Athanasius Kircher, 1671, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Maglev: "The low-speed maglev shuttle that ran from the airport terminal of Birmingham International Airport to the nearby Birmingham International railway station between 1984 and 1995.", by MaltaGC, 2011, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Magnesium: "Crystalised magnesium", by Mark Fergus, CSIRO, 2005, licensed under CC BY 3.0, via Wikimedia Commons. View source. View in tree.
• Magnetic detector: "One of the earliest prototype magnetic detectors, built by inventor Guglielmo Marconi and used in his wireless experiments on board the ship Carlo Alberto in the summer of 1902.", by Alessandro Nassiri for Museo nazionale scienza e tecnologia L. da Vinci, 2012, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Magnetic resonance imaging: "The MRI Scanner, described as the first one ever used, know as the Mark One, created at Aberdeen Royal Infirmary, Scotland. Photo taken in the Suttie Art Space in Aberdeen Royal Infirmary, where the device has been on display since February 2016.", by AndyGaskell, 2016, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Magnetism of the Earth: "Illustration from De Magnete, etc. by William Gilbert (1600, translated 1900), showing iron wires standing on a terrella", by William Gilbert, 1600, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Magnetometer: "Plate XV (Instruments Used in Magnetic Observations), Figure 1, of 1897 publication called Maryland Geological Survey Volume One, with caption "Coast and Geodetic Survey Magnetometer No. 18."", by William Bullock Clark, 1897, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Magnifying glass: "Photo of the Nimrud lens in the british museum", by Geni, 2011, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Mainspring: "Drawing of a clock mainspring from the mid 19th century. WARNING - Never disassemble a watch or clock that contains a mainspring without the proper tools and techniques. The mainspring contains a lot of energy and can release suddenly, causing serious injury.", by Dionysius Lardner, 1858, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Mangalloy: "US Marine Corps M1917 Brodie pattern helmet", by Joshua R. Murray, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Manganese: "Pure (99.99 %) manganese chips, electrolytically refined, typical view of on air oxidized surface, as well as a high purity (99.99 % = 4N) 1 cm3 manganese cube for comparison.", by Alchemist-hp (talk) (www.pse-mendelejew.de), 2010, licensed under FAL, via Wikimedia Commons. View source. View in tree.
• Manned hot air balloon: "The first manned hot-air balloon, designed by the Montgolfier brothers, takes tethered off at the garden of the Reveillon workshop, Paris, on October 19, 1783.", by Claude Louis Desrais, 1783, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Manual vacuum cleaner: "The patent model for Daniel Hess's carpet-sweeper displayed at the Don Aslett Museum of Clean in Pocatello, Idaho; the only physical piece of the sweeper in existence.", by Underneaththesun, 2017, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Maple syrup: "Iconography illustrations in "Customs of the American Indians" by Joseph François Lafitau (published 1724).", by Joseph François Lafitau (1681-1746), 1724, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Margarine: "Margarine.jpg", licensed under CC BY-SA 2.0, via Wikimedia Commons. View source. View in tree.
• Marine chronometer: "Photograph of John Harrison's H4 clock. Low resolution for illustrative purposes only, and to discourage potential commercial use. Shot without flash, 800 ASA setting.", by Phantom Photographer, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Mariner's astrolabe: "Mariner's astrolabe recovered in 1994 from a shipwreck at Ria de Aveiro, Portugal. Circa 1600. Navy Museum in Lisbon.", by Hispalois, 2017, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Maritime flag signalling: "Plate 24. 307 to 324 The Flags of the International Code. 18 illus.(*) 325 The Signal-hoist for the Eddystone Lighthouse, B.D.T.F. 326 Code-signal for the Port of London, B.D.P.Q. 327 Code-signal of SS. Germanic, N.V.B.Q. 328 Code-signal of the Hesperus, M.N.D.L. 329 Code-signal of H.M.S. Devastation, G.R.C.T. 330 "Do you wish to be reported?" B.P.Q. 331 "All safe!" V.K.C. 332 "Report me to Lloyd's Agent." P.D.S. 333 "Do you want assistance?" H.V.F. 334 "Has any accident happened?" B.G.H. (*) There were no vowels in the code at this time, to avoid inadvertent obscenities in code groups! X, Y & Z were also not represented.", by Frederick Edward Hulme, 1896, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Markov chain: "Graph of a Markov chain.", by Joxemai4, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Mars rover: "Sojourner Rover Near The Dice", by NASA, 1997, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Maser: "The first maser (Microwave Amplification by Stimulated Emission of Radiation), invented by Charles H. Townes, James P. Gordon, and H. J. Zeiger at Columbia University in 1953. Townes, Nikolay Basov and Alexander Prokhorov were awarded the 1964 Nobel Prize in Physics for theoretical research that led to the maser. Townes is shown with the device. This was an ammonia maser. The brass box is the vacuum chamber through which the ammonia ions travel. The ammonia gas nozzle is at left. The four rods at center are the quadrupole filter which filters out the lower state ammonia molecules, leaving a population inversion. In the resonant cavity at right, stimulated emission of microwaves by the molecules excites standing waves in the cavity, which pass out through the vertical output waveguide. The devices at bottom are vacuum pumps which evacuated the box. Masers are used as the timekeeping elements in atomic clocks, and as extremely low-noise microwave amplifiers in radio telescopes. Alterations to image: cropped out rest of magazine cover", by Dan Rubin, 1958, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Masking tape: "Eine Rolle breites Malerkrepp-Klebeband.", by Neitram, 2011, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Mass spectrometer: "Replica of Francis William Aston's third mass spectrometer.", by Jeff Dahl, 2009, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Massive parallel sequencing: "HiSeq2000", by RE73, 2012, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Maxwell's equations: "Plaque showing Maxwell's equations at the Edinburgh statue.", by FF-UK, 2017, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Maya numerals and zero: "A section of page 43b of the Dresden Codex", by Unknown authorUnknown author, 1200, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Measuring rod: "The Nippur cubit. Exhibit in the Archeological Museum of , Turkey", by Aeroid, 2015, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Mechanical calculator: "Pascaline-CnAM 823-1-IMG 1506-black.jpg", by Rama, 2016, licensed under CC BY-SA 3.0 fr, via Wikimedia Commons. View source. View in tree.
• Mechanical television: "A woman watching an early homemade experimental mechanical television receiver in 1928, from Hugo Gernsback's magazine Science and Invention. During the 1920s some radio stations began broadcasting experimental television programs, which could be viewed by mechanical "televisor" receivers like this one. The video signal from the receiver (left) is applied to a neon lamp in the viewer (right). In front of the lamp a metal disk with holes rotates, creating the scan lines of the image. This created a dim monochrome orange image 1.5 inches (4 cm) square with 48 scan lines at 7.5 frames per second, visible within the viewing cone, which the woman is watching. These mechanical-scan television technologies never achieved images of sufficiently high quality to catch on with the public, and were superseded by electronic scan television broadcasts in the 1930s.", by Unknown authorUnknown author, 1928, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Mechanical wood pulping: "A photo of the original F.G. Keller wood grinding (wood-cut) machine (used for pulping wood for paper making).", by Peter Burger, 2002, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Mechanized submarine: "Plongeur.jpg", licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Media streaming: "This file was uploaded with Commonist.", by Lionel Allorge, 2013, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Medical respirator: "John Stenhouse's mask.png", licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Mellotron: "Mellotron, Museum of Making Music Edit rotated to correct the horizontal inclination erased a warning plate stated "PLEASE DO NOT TOUCH"", by Mellotron, Museum of Making Music.jpg: doryfour derivative work: User:Clusternote, 2012, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Mendelian inheritance: "Mendels rules (Myosotis)", by Photograph by S. Metzing-Blau, Germany, 2010, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Meniscus lens: "By Paul Chin (paul1513); self created; block diagram of Wollaston Meniscus, the first photographic camera lens.", by Paul1513 at English Wikipedia, 2010, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Mercator projection: "Carta do Mundo de Mercator (1569)", by Gerardus Mercator, 1569, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Mercury: "Mercury, Cinnabar", by Parent Géry, 2009, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Mercury battery: "Soviet-era mercury battery "RC-53M" (320mAh) built in 1989", by Andshel, 2011, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Mercury thermometer: "Mercury-in-glass thermometer for measurement of room temperature. Celsius scale.", by Anonimski, 2013, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Mercury-arc valve: "In-service device, as you can see the blue light phenomena in the center bottom (the liquid mercury cathode spot)", by Secretlondon, 2005, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Mercury-vapor lamp: "A pole-mounted yard light with a mercury-vapor lamp, approximately 15 seconds after starting. PLEASE NOTE: this image is not color-correct. Although mercury-vapor lamps do have a bluish tint to them, the tint is not quite this intense. FUTURE EDITORS: if anyone here has the ability to color-correct this image or if you have a different image that is more suitable than this one, please feel free to replace this image with a color-corrected version or suitable replacement.", by Torindkflt, 2007, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Merge sort: "Mergesort algorithm diagram.png", licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Mesoamerican calendars: "Stone version of the Maya 260 calendar at the Smithsonian.", by MBisanz, 2009, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Metal-cased rocket artillery: "Attributed to Payag Indian (active mid-17th century) The Battle of Samugarh, c. 1658 Painting Mughal , 17th century Mughal period, 932-1274/1526-1858 Creation Place: India Gray-black ink, opaque watercolor, gold and metallic silver paint over white wash on off-white paper Sheet: 28.5 x 38.5 cm (11 1/4 x 15 3/16 in.) Harvard Art Museums/Arthur M. Sackler Museum, Gift of Stuart Cary Welch, Jr. , 1999.298 Department of Islamic & Later Indian Art , Division of Asian and Mediterranean Art", by Payag, 1658, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Metal-halide lamp: "Closeup of a 150 watt tubular, double ended metal halide lamp @ approx. halfway through warmup. METAL HELIDE LAMP", by Dave H. Ozguy89 at en.wikipedia, 2008, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Metallic nib: "Illustration of a pointed pen labelling the different parts.", by NotAnonymous, 2009, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Metalorganic vapour-phase epitaxy: "MOCVD stands for "metalorganic chemical vapour deposition", but it is also known by other names and acronyms. It is a process by which the compound InP can be formed.", by Wikipedia user Crystalgrower, 2006, licensed under CC BY 3.0, via Wikimedia Commons. View source. View in tree.
• Method of exhaustion: "English: Pi approximationThis is hardly how Archimedes approximated Pi, he didn't go from regular pentagon to hexagon to octagon, but started with a regular hexagon and doubled the number of sides.", by Original: Fredrik Vector: Leszek Krupinski, 2006, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Method of indivisibles: "Extrait d’un traité de Bonaventura Cavalieri servant de logo à la Société canadienne d'histoire et de philosophie des mathématiques", by Bonaventura Cavalieri original uploader : Cbyd at French Wikipedia, 1653, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Metre: "One of the historical (18th century), standard-meter (mètre-étalon) by Chalgrin located at 36, rue de Vaugirard in Paris", by LPLT, 2010, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Metric system: "Four metric measuring devices - a tape measure, a thermometer, a one kilogram weight and an electrical multimeter. These instruments were selected to show some of the units of measure that part of the metric system (or more correctly) SI - centimetres, kilograms, degrees Celsius, amperes, volts and ohms.", by Martinvl, 2011, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Metronome: "Metronome Maëlzel", by Myself, 2008, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Meusnier's dirigible: "Airship designed by French engineer and general Jean-Baptiste Marie Meusnier de La Place (1754-1793)", by Jean-Baptiste Marie Meusnier de La Place, 1784, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Microblogging: "A tweet posted to Twitter in 2007: "catching bugs. squish squish!"", by Karen, 2009, licensed under CC BY 2.0, via Wikimedia Commons. View source. View in tree.
• Microcentrifuge: "Tabletop centrifuge.", by Magnus Manske, 2004, licensed under CC BY 1.0, via Wikimedia Commons. View source. View in tree.
• Microcode: "Die shot of Motorola 68000 microprocessor (MC68000L12, 2A72E mask).", by Pauli Rautakorpi, 2014, licensed under CC BY 3.0, via Wikimedia Commons. View source. View in tree.
• Microcomputer: "Micral computer. Exposed in Lyon", by Rama, 2011, licensed under CC BY-SA 2.0 fr, via Wikimedia Commons. View source. View in tree.
• Microlith: "Kebaran culture microliths 22000-18000 BP", by Gary Todd, 2019, licensed under CC0, via Wikimedia Commons. View source. View in tree.
• Micropipette: "Collage. Clockwise from top left: various sizes of micropipettes, a graduated serological pipette attached to an electronic manual pipetter, and two pasteur pipettes. From File:Pipettes colours.jpg, File:Pipetter and serological pipette.jpg and File:Pasteur Pipets.jpg.", by User:Squidonius, myself, and User:Beliason (assumed)., 2023, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Microprocessor: "A processor Intel C4004 with grey traces (no gray trace version).", by Thomas Nguyen, 2016, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Microtome: "Figures of 'an eighteenth century Microtome'. Published anonymous, Journal of the Royal Microscopical Society, 1910, pages 779-782. The Royal Microscopical Society, Oxford, England. Block of figures used from 1774 publication by John Hills, M.D. Member of the Imperial Academy. London 1774, 2nd edition 64 pages.", by John Hills 1774, File assembled by Mirko Junge from scanns fount at archive.org, 1774, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Microwave oven: "Panasonic microwave oven NN-SD69LS", by Mrbeastmodeallday, 2022, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Military submersible: "Bushnell's "Turtle", Oceanographic Museum, Monaco", by Zenit, 2009, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Milk chocolate: "Milka Alpine Milk Chocolate bar 100g with chunks broken off. (Purchased on UK market in mid-2021).", by Ubcule, 2021, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Milk-cream separator: "Promotional slide produced by Scott & Van Altena of 6 East 39th St., New York City, for the Educational Department of the De Laval Separator Company, probably in the 1920s. Donated to the Community Archives of Belleville and Hastings County by Mike and Sue Mills in October 2015.", by Community Archives, 1920, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Mills bomb: "Mills bombs. From left to right : N°5, N°23, N°36.", by J-L Dubois, 2007, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Miniature neon lamp: "Close-up view of an NE-2 (5mm diameter) type neon lamp. Both electrodes appear to glow simultaneously due to being powered by 60Hz alternating current, with the exposure time being longer than a full current cycle.", by Junkyardsparkle, 2015, licensed under CC0, via Wikimedia Commons. View source. View in tree.
• Minié ball: "Minie Balls - rifled musket bullets. From left to right: .557 Enfield Minie Bullet, Burton Pattern Minie Bullets .58 Springfield (x 2), Williams Bullet missing zinc base, .69 Caliber Minie Bullet for modified 1842 Springfield Musket.", by Mike Cumpston, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Mining: "This is an adit (horizontal or sloping mine entrance) in the Johannesburg municipality, near the suburb of Roodepoort. It is part of a chain of similar adits along a surface outcrop of the Roodepoort gold reef of the Witwatersrand, South Africa.", by Manyeva, 2013, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Miquelet lock: "Flintlock Miquelet. Turkey XVIth century. Iron. Weapons Department, Museum of Art and Industry in Saint-Étienne, France.", by Hélène Rival, 2012, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Mirror: "Obsidian mirrors. Çatalhöyük, 6000-5500 BC. Museum of Anatolian Civilizations, Ankara.", by Zde, 1999, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Mirror galvanometer: "Sir William Thomson, Lord Kelvin, (1824-1907) was Professor of Natural Philosophy at Glasgow University, and was well known for his work in many branches of physics, including electricity. The first transatlantic telegraph cable was laid in 1858, reducing the time it took for messages to cross from days or months to hours. The success of the system relied on an instrument that could detect the tiny electrical signals that had passed so far under the sea. Thomson's galvanometer was the only instrument sensitive enough to detect reliably the first transatlantic telegraph messages. Made by J White.", by Science Museum London / Science and Society Picture Library, 2013, licensed under CC BY-SA 2.0, via Wikimedia Commons. View source. View in tree.
• Mitrailleuse: "Montigny_Mitrailleuse, developed by the Belgian Armory factory of Joseph Montigny between 1859 and 1870", by Unknown authorUnknown author, 1870, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Mobile radio telephone: "A mobile radio telephone.", by Hackgillam at English Wikipedia, 2007, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Modem: "The back of a Teletype Model ASR-33 teleprinter with a Bell 101C modem installed in the pedestal, circa 1963.", by Retro-Computing Society of Rhode Island, 2023, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Modern ballpoint pen: "Schneider K15 ballpoint pen and the pen in parts", by No machine-readable author provided. Pavel Krok~commonswiki assumed (based on copyright claims)., 2005, licensed under CC BY-SA 2.5, via Wikimedia Commons. View source. View in tree.
• Modern barbed wire: "BarbedWirePatentGlidden.jpg", licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Modern cryptography: "Simple diagram of a symmetric encryption scheme", by Michel Bakni, 2024, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Modern evolutionary synthesis: "Inputs to the "modern synthesis" (ca. 1950) of evolutionary biology, with other topics that were not input until decades later, so showing the limits of the synthesis.", by Ian Alexander, 2017, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Modern gas turbine: "Gas turbine designed by Ægidius Elling (improved version of his 1903 patent), installed at Christiania Seildugsfabrikk", by Photographer anonymous, 1906, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Modern guitar: "Spanish guitarist Rafael Serrallet posses in 2008 in Valencia with a 19th century guitar made by Manuel de Soto y Solares", by Mestremendo, 2008, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Modern oil well: "postcard, galicia 1881,", by The original uploader was Silar at English Wikipedia., 2006, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Modern Portland cement: "A pallet of Portland cement bags used for construction.", by KVDP, 2008, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Moka pot: "Moka coffee machine", by Alexandre Albore, 2006, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Molecular-beam epitaxy: "English: Molecular-beam epitaxy system at LAAS-CNRS technological facility in Toulouse, France. Français : Système d'épitaxie par jet moléculaire à la centrale de technologie du LAAS-CNRS à Toulouse, France.", by QGravelier, 2021, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Molybdenum: "Molybdenum, ebeam remelted macro crystalline fragment. Purity 99.99 % (= "4N"), as well as a high purity single crystalline (99.999 % = 5N) 1 cm3 molybdenum cube for comparison.", by Alchemist-hp (talk) (www.pse-mendelejew.de), 2010, licensed under FAL, via Wikimedia Commons. View source. View in tree.
• Monolithic integrated circuit: "Apollo Guidance Computer NOR-gate die shot.", by The original uploader was Grabert at German Wikipedia., 2005, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Monosodium glutamate: "AJI-NO-MOTO", by Ajinomoto Co., Inc., 2008, licensed under CC BY 2.5, via Wikimedia Commons. View source. View in tree.
• Monte Carlo method: "Comparaison de l'évolution de la somme de 10 tirages consécutifs entre 0 et 100 réalisés N fois. La distribution se rapproche d'une distribution normale quand N augmente.", by Titouan Christophe, 2014, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Moog synthesizer: "photo", by AnonymousUnknown author, 1970, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Moon landing: "Astronaut Edwin E."Buzz" Aldrin Jr., Lunar Module pilot, is photographed during the Apollo 11 extravehicular activity on the Moon. He has just deployed the Early Apollo Scientific Experiments Package (EASEP). In the foreground is the Passive Seismic Experiment Package (PSEP); beyond it is the Laser Ranging Retro-Reflector (LR-3); in the center background is the United States flag; in the left background is the black and white lunar surface television camera; in the far right background is the Lunar Module "Eagle". Astronaut Neil A. Armstrong, commander, took this photograph with a 70mm lunar surface camera.", by NASA Neil A. Armstrong, 1969, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Moore tube: "1904 Photograph illustrating interior lighting by the first installation of Moore tubes, which were the first commercially viable electric discharge lamps. The photograph is of the interior of a hardware store in Newark, New Jersey. The image was digitized on June 25, 2010 from an original in the New York City Public Library; the contrast was further adjusted by the uploader. Item/Page/Plate: 5.352 Notes: Courtesy of D. McFarlan Moore. Source: "The Pageant of America" Collection / v.5 - The epic of industry / (Published photographs) Source Description: Approx. 8,000 photographs Location: Stephen A. Schwarzman Building / Photography Collection, Miriam and Ira D. Wallach Division of Art, Prints and Photographs Digital ID: 95160 Record ID : 131875", by Daniel McFarlan Moore, 1904, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Morphine: "Structure of", by Fuse809 (talk), 2014, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Morse code: "Chart of the Morse code letters and numerals.", by Rhey T. Snodgrass & Victor F. Camp, 1922, 2008, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Mortar and pestle: "En Gev Epipaleolithic period Basalt Israel Antiquities Authority H: 29 cm; Diam: 25-28 cm; Weight: 11 kg Prehistoric Periods The Israel Museum, Jerusalem Archaeology. Stone Age Stone Mortar & Pestle, Kebaran culture, 22000-18000 BP Israel Museum, Jerusalem, Israel. Complete indexed photo collection at WorldHistoryPics.com.", by Gary Todd, 2018, licensed under CC0, via Wikimedia Commons. View source. View in tree.
• Mortise and tenon: "Stool, low, woven seat", 1991, licensed under CC0, via Wikimedia Commons. View source. View in tree.
• MOS DRAM: "Memory Card with Integrated circuit (Micron MT4C -1024 mebibit (1 Megabit)), Dynamic Random Access Memory (DRAM) chips. Die size is 8662x3969µm. This device is from 1989 as readable on the printed circuit board itself. Datasheet available: [1]", by ZeptoBars, 2012, licensed under CC BY 3.0, via Wikimedia Commons. View source. View in tree.
• MOS SRAM: "Static Ram chip form a NES clone. 2K X 8 bit", by Satyamfifa, 2010, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• MOSFET: "Two test MOSFETS of different lengths and widths, on a metal-gate MOS chip. Modified from the Public Domain image MOS 768x576.jpg; straightened, cropped, enhanced, labeled.", by Dicklyon at English Wikipedia, 2006, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Motorboat: "Diagram of the first internal combustion engine,the Pyreolophore, of 1806 which was powered by a mixture of coal dust and lycopodium powder.", by Nicéphore Niépce ( 1765 – 1833) and Claude Niépce (1763 – 1828), 1806, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Motorcycle: "Daimler Reitwagen aus dem Jahr 1885 im Mercedes Benz Museum in Stuttgart", by Wladyslaw, 2006, licensed under CC BY-SA 2.0 de, via Wikimedia Commons. View source. View in tree.
• Motorized air compressor: "DRAFT Trade card of G Medhurst, scale maker", 1810, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Mould-board plough: "Chinese Iron plow", by Sung Ying Hsing, Reference: "Chinese technology in the 17th century", 1637, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Mousterian stone tool: "Mousterian point - Different views of the same specimen", licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Movable type: "Frame holding wooden moveable type for Chinese characters. 29.5 × 21.5 × 3.5 cm. Late Ming dynasty or early Qing dynasty. Held at Ningxia Museum, Yinchuan.", by BabelStone, 2016, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Movie camera: "Charles Kayser of the Thomas Edison laboratory with an early version of the Kinetograph, the camera developed to shoot films for the Kinetoscope movie exhibtion system, ca. 1891–94", by National park Service, 1891, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Moving coil galvanometer: "An early D'Arsonval galvanometer, which became the design used in modern moving coil ammeters. It consists of a small coil of fine wire suspended between the poles of a horseshoe magnet by a torsion fiber. When an electric current passes through the coil it turns to be parallel with the field, twisting the fiber, moving the pointer up the scale. When the torque of the coil balances the torque of the fiber, the pointer stops. From Hooke's law, the torque of the fiber is proportional to the angle of twist, so the angle of the pointer is proportional to the current.", licensed under CC BY 4.0, via Wikimedia Commons. View source. View in tree.
• Moving coil oscillograph: "Oscillograph Duddell Moving Coil.png", licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• MP3 audio compression: "The mp3 logo of the Fraunhofer Institute for Integrated Circuits.", by Unknown authorUnknown author, 2007, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• MP3 player: "THE mp3 player strobist note: still life table, single flash/bank here -> https://www.flickr.com/photos/e-coli/2526204838/ note lampiste, set con 1 sola torcia: Tavolo da Still life Flash Sunpak auto 383s, comandato tramite cavo hot-shoe/hot-shoe, montato su cavalletto Modificatore di luce: Small Bank ottenuto con un porta camicie Ikea 45x56x20cm posizionato frontalmente al tavolo da still-life modifiche in photoshop: saturazione/contrasto/luminositàcurve/livelli aumento nitidezza tramite layer hi-pass note personali: il riflesso non è aggiunto in postproduzione English: Strobist notes: (DIY) Table "still life", single flash/bank Here -> flickr.com/photos/e-coli/2526204838/ Lighting notes, set with 1 single torch: Table "Still Life", Flash Sunpak auto 383s, operated via cable hot-shoe/hot-shoe, mounted on a tripod with a modified light: Small bank accomplished with an Ikea door shirt with dimensions 45 x 56 x 20 cm positioned in front of the table "still life". (Ikea 701.025.28) Changes in Photoshop: Saturation / contrast / light curve / sharpness levels increased with hi-pass layer Personal notes: The reflection is not added in post-production.", by Michele M. F. from Milano, Italy, 2008, licensed under CC BY-SA 2.0, via Wikimedia Commons. View source. View in tree.
• mRNA vaccine: "mRNA in vitro transcription and innate immunity activation. (A) mRNA in vitro transcription. Using DNA with the antigen-encoding sequence as template, mRNA in vitro transcription products contain single-stranded RNA (ssRNA), double-stranded RNA (dsRNA), etc. The ssRNA structure normally includes five-prime cap (5′ cap), five-prime untranslated region (5′ UTR), open reading frame (ORF) region, three-prime untranslated region (3′ UTR), and poly (A) tail structure. (B) RNA translation and antigen presentation. Through endocytosis, mRNAs enter the cytoplasm. Some mRNAs combine with ribosomes of the host cell and translate successfully. Antigen proteins can be degraded to antigenic peptides by proteasome in the cytoplasm and presented to cytotoxic T lymphocytes (CTLs) via major histocompatibility complex (MHC) I pathway. Or, they can be released out of the host cell and taken up by DCs. Then, they are degraded and presented to helper T cells and B cells via MHC-II pathway. B cells can also recognize released antigen proteins. (C) Self-adjuvant effect. Various of pattern recognition receptors (PRRs) can recognize mRNA in vitro transcription product. ssRNA can be recognized by endosomal innate immune receptors (e.g., Toll-like receptor 7 (TLR7), TLR8). dsRNA can be recognized by endosomal innate immune receptors (e.g., TLR3) and cytoplasmic innate immune receptors (e.g., protein kinase RNA-activated (PKR), retinoic acid-inducible gene I protein (RIG-I), melanoma differentiation-associated protein 5 (MDA5), and 2′-5′-oligoadenylate synthase (OAS). Based on those, mRNA products can stimulate the secretion of pro-inflammatory cytokines and type I interferon (IFN), which leads to antigen-presenting cells (APCs) activation and inflammatory reaction. However, they can also activate antiviral enzymes that cause stalled mRNA translation and mRNA degradation.", by Shuqin Xu, Kunpeng Yang, Rose Li, and Lu Zhang, 2020, licensed under CC BY 4.0, via Wikimedia Commons. View source. View in tree.
• Mudbricks: "New mudbricks in Palestine 2011", by Whiteghost.ink, 2011, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Multi-touch: "On the left, x-y multi touch capacitance screen prototype developed at CERN in 1977; on the right, self capacitance screen developed at CERN in 1972.", by Maximilien Brice, 2010, licensed under CC BY 2.0, via Wikimedia Commons. View source. View in tree.
• Multi-touch smartphone: "Original iPhone 8GB, iPhone 3G 16GB and iPhone 4 32GB.", by Yutaka Tsutano, 2010, licensed under CC BY 2.0, via Wikimedia Commons. View source. View in tree.
• Multi-tube seed drill: "ChineseSeedDrill1637", by Sung Ying Hsing. Reference "Chinese technology in the 17th century", 1637, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Multistage rocket: "An illustration of a multistage rocket from the Huolongjing, a Chinese military treatise written in the 14th century by Jiao Yu and Liu Ji, the preface added in the year 1412. This missile was called the "fire-dragon issuing from the water" (huo long chu shui), a two-stage rocket. When the carrier or booster rockets were about to burn out they automatically ignited a swarm of smaller rocket-arrows which issued through the dragon mouth and fell upon the intended enemy target. The design seems to have been for use mainly in naval warfare. Since the trajectory was very flat the weapon may be regarded as an ancestor of the modern exocet. This illustration also appears on page 510 of Joseph Needham's book Science and Civilization in China: Volume 5, Part 7.", by PericlesofAthens, 2007, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Multivibrator: "An early vacuum tube astable multivibrator oscillator, being used with a tuning fork to calibrate a wavemeter, France, around 1920. The Abraham-Bloch multivibrator (small box at left), a two-tube cross-coupled oscillator circuit invented in 1918 by French engineers Henri Abraham and Eugene Bloch, was called a multivibrateur because its square wave output contained many harmonic components, in contrast to ordinary sine wave oscillators. Harmonics up to 150 times the fundamental frequency could be detected. The photo shows an Abraham-Bloch multivibrator being used to calibrate a "wavemeter" (center). Wavemeters were instruments that measured frequency with a precision tuned circuit. They were used to measure the frequency of early radio transmitters to certify that they were broadcasting on their correct government-mandated frequency in compliance with law. The multivibrator oscillator (left) was first set to exactly 1000 Hz using a precision tuning fork frequency standard (small device in front of oscillator). The oscillator output and a signal from the tuning fork were applied to a detector and audio amplifier (right). The nonlinear detector tube mixed the two signals, producing a beat (heterodyne) signal at the difference between the two frequencies, which was amplified until it was audible as a tone in the earphones. The frequency of the multivibrator was adjusted until the beat decreased to zero. This meant the two frequencies were the same. Then the output of the multivibrator was applied to the wavemeter (center). The multivibrator output contained harmonics at exact multiples of 1 kHz, up to several hundred kilohertz, the radio frequency range used by early transmitters. The wavemeter was tuned to resonance with one of the harmonics of the oscillator, and the wavemeter's scale was set to show the correct frequency. Caption: "To the left is shown the multivibrator, and close to it is the tuning fork mentioned by the author. To the right is the amplifier-detector, while in the center is a special wavemeter" Alterations to image: Partially removed aliasing artifacts (crosshatched lines) introduced during scanning of original halftone image, using Gimp FFT filter, and lightened and increased contrast to bring out more detail.", by Capitaine Metz, 1920, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Mummification: "Mummified body of a child of indeterminate sex, about five years old. The mummy is covered with polychrome two templates located on the chest and legs and fastened with bandages.", by Col·lecció Eduard Toda, 2013, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Muscle cuirass: "Museo archeologico regionale paolo orsi, corazza in bronzo, da tomba 5 necropoli della fossa, 370-340 ac.", by sailko, 2009, licensed under CC BY 2.5, via Wikimedia Commons. View source. View in tree.
• Musical bow: "MusicalBow.gif", licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Musical Instrument Digital Interface: "Power Conditioner Behringer SNR2000 Denoiser Mark of the Unicorn MIDI Express XT E-mu Extreme Lead-1 E-mu Mo'Phatt E-mu Turbo Phatt Alesis QSR Behringer RX1602  8ch/12in Line Mixer E-mu Proteus 1 Pop/Rock Clavia Nord Rack M-Audio Oxygen 8 keyboard", by Blurred Ren, 2007, licensed under CC BY 2.0, via Wikimedia Commons. View source. View in tree.
• Musical notation: "Hurrian hymn. (Transcription: below double-scribed line, Lines 1-6: Line 1--qáb-li-te 3 en:ir (cuneiform)-bu-en:te (cuneiform) 1 qáb-li-te 3 ša-aḫ-ri 1 en:i (cuneiform)-šar-te 10 uš-ta-en:ma (cuneiform)-en:a (cuneiform)-ri Line 2--ti-en:TI (cuneiform)-mi-šar-te 2 zi-ir-te 1 ša-[a]ḫ-en:ri (cuneiform) 2 ša-en:aš (cuneiform)-ša-te 2 ir-bu-te 2 (Transcription: below double-scribed line, Lines 1-6: Line 1--qáb-li-te 3 ir-bu-te 1 qáb-li-te 3 ša-aḫ-ri 1 i-šar-te 10 uš-ta-ma-a-ri Line 2--ti-ti-mi-šar(LUGAL)-te 2 zi-ir-te 1 ša-[a]ḫ-ri 2 ša-aš-ša-te 2 ir-bu-te 2", by Unknown authorUnknown author, 2006, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Muslin: "1665 depiction of Prince Dara Shikoh and Sulaiman Shikoh Nimbate wearing fine muslin robes", by Unknown authorUnknown author, 2017, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Mysorean rocket: ", Mysore rocket man by British artist Robert Home. Indian soldier of Tipu Sultan's army is shown lifting a rocket from ground, holding its head-end by one hand and lighting the fuse by another. The traditional costume of Tipu's infantry generally consists of a 'Tyger Jacket', a long purple woollen shirt with white diamond formed spots on it. On his head the soldier wears a red and white muslin turban, matching the red sash around his waist. Beneath his white trousers, his legs and feet are bare. Artist: Home, Robert, born 1752 - died 1834 (artist) Height: 10.2 cm, Width: 15.8 cm", by Robert Home, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Nailed horseshoe: "A range of horseshoes, aluminium race plates (light coloured) and bullock shoes in lower right.", by Cgoodwin, 2009, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Nålebinding: "Pair of socks 300-500 Egypt Wool (knitted) These socks are the earliest knitted items in the V&A's collection. Made in 300-499 AD, they were excavated in Egypt at the end of the 19th century. They have a divided toe and are designed to be worn with sandals. The socks are knitted in stocking stitch using three-ply wool and the single-needle technique. This type of knitting is a slow technique more like sewing. It was a forerunner of the faster method of knitting with two or more needles. Textile historians often find it difficult to tell whether early knitted objects are made using a single needle, as here, or using more than one needle, as the finished articles are so similar in appearance. Given by Robert Taylor", by David Jackson, 2010, licensed under CC BY-SA 2.0 uk, via Wikimedia Commons. View source. View in tree.
• Napier's bones: "An ivory set of Napier's Bones from around 1650. An exhibit in the National Museum of Scotland.", by Kim Traynor, 2012, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Natural selection: "Charles Darwin's 1837 sketch, his first diagram of an evolutionary tree from his First Notebook on Transmutation of Species (1837).", by Charles Darwin, 1837, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Naval mine: "A Ming Dynasty Chinese illustration of a naval mine from the 14th century military treatise of the Huolongjing, compiled by Jiao Yu and Liu Ji, with Jiao's preface added in 1412. This particular sea mine was called the 'submarine dragon king' (shui di long wang pao). The firing mechanism consists of a floated incense-stick which lights the fuse when it burns down, this last being contained in a length of goat's intestine, and connecting with the explosive charge which is floated at a certain depth submerged below. This illustration also appears on page 206 of Joseph Needham's Science and Civilization in China: Volume 5, Part 7.", by PericlesofAthens, 2007, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Nd:YAG laser: "Continuum Powerlite 8000 Nd:YAG laser.", by Kkmurray, 1997, licensed under CC BY 3.0, via Wikimedia Commons. View source. View in tree.
• Neodymium: "Ultrapure neodymium under argon, 5 grams. Original size in cm: 1", by Unknown authorUnknown author, licensed under CC BY 3.0, via Wikimedia Commons. View source. View in tree.
• Neodymium magnet: "28 nickel-plated neodymium magnet cubes, 0.5 cm edge length each.", by Unknown authorUnknown author, licensed under CC BY 3.0, via Wikimedia Commons. View source. View in tree.
• Neon: "Spectrum = gas discharge tube: the noble gas: neon Ne. Used with 1,8kV, 18mA, 35kHz. ≈8" length.", by Alchemist-hp (talk) (www.pse-mendelejew.de), 2006, licensed under GFDL 1.2, via Wikimedia Commons. View source. View in tree.
• Neon lighting: "Image of a neon filled discharge tube shaped like the element’s atomic symbol "Ne". Example of neon lighting. The letter "N" is about 75 cm tall.", by User:Pslawinski, 2005, licensed under CC BY-SA 2.5, via Wikimedia Commons. View source. View in tree.
• Neptunium: "This nickel-clad neptunium sphere was used to experimentally determine the critical mass of Np at Los Alamos National Lab.", by Los Alamos National Lab., 2002, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Nernst lamp: "Nernst lamp", licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Network with end-to-end principle: "CYCLADES Network Model.", by Michel Bakni, 2017, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Neural language model: "A diagram for a one-unit recurrent neural network (RNN). From bottom to top : input state, hidden state, output state. U, V, W are the weights of the network. Compressed diagram on the left and the unfold version of it on the right.", by fdeloche, 2017, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Neuron doctrine: "Drawing of the cells of the chick cerebellum by Santiago Ramón y Cajal, from "Estructura de los centros nerviosos de las aves", Madrid, 1905?.", by Santiago Ramón, 1905, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Neutrino: "The first use of a hydrogen bubble chamber to detect neutrinos, on November 13, 1970. A neutrino hit a proton in a hydrogen atom. The collision occurred at the point where three tracks emanate on the right of the photograph.", by Argonne National Laboratory, 1970, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Neutron: "A schematic diagram of the experiment James Chadwick used to discover the neutron in 1932. At left, a polonium source was used to irradiate beryllium with alpha particles, which induced a type of uncharged radiation initially thought to be gamma rays. When this radiation struck paraffin wax, protons were ejected with ca. 5.5 MeV kinetic energy. The protons were observed using a small ionization chamber, called a counter, that detected a signal recorded on an oscillograph. Adapted from J. Chadwick, The Existence of a Neutron, Proc. Royal Society London, Series A, 136, 692-708, 1932.", by Bdushaw, 2017, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• New quadrant: "Horary quadrant - print of drawing", by George Fisher, 2013, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Newcomen atmospheric engine: "Reverse 2s Colonial currency from the Province of New York. Signed by John H. Cruger and William Waddell.(Friedberg Colonial ref# NY-173).", by National Museum of American History, 2014, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Newspaper: "Title page of the Relation aller Fürnemmen und gedenckwürdigen Historien from 1609. The German-language 'Relation' had been published by Johann Carolus at the latest since 1605 in Strassburg, and is recognized by the World Association of Newspapers as the world's first newspaper.", by University library of Heidelberg, Germany, 1609, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Newton's laws of motion: "A page from the 1726 edition of the Principia.", by Isaac Newton, 1726, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Nichrome heating element: "Light Label Electric tabletop burner KCK-L103.", by photo: Qurren (talk), 2010, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Nickel: "Electrolytically refined pure (99.9 %) nickel nodules, and a high purity (99.99 % = 4N) 1 cm3 nickel cube for comparison. Crystallized nickel-electrolyte salts (green) can be seen in the pores of the nodules.", by Alchemist-hp (talk) (www.pse-mendelejew.de), 2010, licensed under FAL, via Wikimedia Commons. View source. View in tree.
• Nickel–cadmium battery: "NiCd various.jpg", licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Nickel–iron battery: "Nickel–iron batteries under the "Exide" brand originally developed in 1901 by Thomas Edison. Exide acquired the Edison Storage Battery Company in 1972 and manufactured this type of batteries until 1975. Photo taken at the Thomas Edison National Historical Park in West Orange, New Jersey.", by User:z22, 2013, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Niobium: "High purity (99.995 % = 4N5) niobium crystals, electrolytic made, as well as a high purity (99.95 % = 3N5) 1 cm3 anodized niobium cube for comparison.", by Alchemist-hp (talk) (www.pse-mendelejew.de), 2010, licensed under FAL, via Wikimedia Commons. View source. View in tree.
• Nipkow disk: "An early mechanical-scan television receiver from the 1930s. Dozens of early stations experimented with television broadcasting using these mechanical-scanning systems during the 1920s and 30s. It uses a Nipkow disk, a spinning metal disk with a spiral pattern of holes in it. A neon light behind the disk, shining through the holes, creates the scan lines of the TV image. The image is only about one inch (3 cm) square so it is viewed through the magnifying lenses shown. The video signal from the receiver (bottom) is applied to the neon light, varying its intensity, to create the different tones of the monochrome image. Different TV stations used different numbers of scan lines and frame rates, and this receiver has two lenses and two neon lights, so it was able to receive TV broadcasts with two different standards, probably a 48 line, 15 frames per second broadcast and a 60 line, 20 frames per second broadcast.", by Holger.Ellgaard, 2012, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Nitric acid: "Acido nitrico riscaldato con rilascio di biossido d'azoto. Ho creato io questa immagine. --Fabexplosive 20:38, 20 apr 2006 (CEST) Categoria:Immagini di chimica", by The original uploader was Fabexplosive at Italian Wikipedia., 2006, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Nitrocellulose film: "Light box displaying a nitrate photograph negative panorama which is suffering from deterioration. Image shows a military unit in front of a stone building / Négatif panoramique sur support de nitrate, montrant des signes de détérioration, affiché sur un Title / Titre : Light box displaying a nitrate photograph negative panorama which is suffering from deterioration. Image shows a military unit in front of a stone building / Négatif panoramique sur support de nitrate, montrant des signes de détérioration, affiché sur un négatoscope. L’image représente une unité militaire devant un édifice en pierre Date(s) : June 21, 2011 / 21 juin 2011 Credit / Mention de source : Library and Archives Canada / Bibliothèque et Archives Canada Description : Nitrate Film Preservation Facility / Centre de préservation de pellicule de nitrate", by Library and Archives Canada, 2011, licensed under CC BY 2.0, via Wikimedia Commons. View source. View in tree.
• Nitrogen: "Liquid nitrogen", by GOKLuLe, 2011, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Nitroglycerin: "Chemical structure of nitroglycerin", by BartVL71, 2008, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Nixie tube: "Cropped from PD image Image:Anzeigen(Displays).jpg.", by Haseluenne, 2007, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Nixtamalization: "Hominy - maize treated with lime (nixtamalization)", by Glane23, 2008, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Noise-cancelling headphones: "Bose QuietComfort 25 Acoustic Noise Cancelling Headphones with Carry Case", by Florian Fuchs, 2016, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Nonius: "Original nonius", by Henrique Leitão, 2000, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Normalsegelapparat: "Otto Lilienthal performing one of his gliding experiments.", by Unknown authorUnknown author, 1894, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Northrop loom: "Weaving machine (Brandname Draper) in The American Textile Museum (Lowell, Mass. USA) - Be careful! The title of this image is not correct!", by švabo, 1999, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Nottingham lace curtain machine: "Industry during the First World War- Leicestershire A female worker replaces empty spools of thread in a lace curtain machine in a Nottingham factory in September 1918.", by George P. Lewis, 1918, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Nuclear fission: "Illustration of a typical nuclear fission reaction", by MikeRun, 2017, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Nuclear magnetic resonance: "Nuclear Magnetic Resonance spectrometer made by Bruker which operates at 700 MHz", by Mike25, 2008, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Nuclear power: "The first production of usable nuclear electricity by Argonne National Laboratory in Idaho occurred in December 20, 1951, when four light bulbs were lit with electricity generated from the EBR-1 reactor.", by Unknown authorUnknown author, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Nuclear power plant: "“World's first nuclear power plant in Obninsk”. The world's first nuclear power plant in Obninsk, which was shut down in 2002 to house a nuclear power museum.", by Pavel Bykov / Павел Быков, 2009, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Nuclear submarine: "USS Nautilus (SS-571), the U.S. Navy's first nucelar-powered submarine, on its initial sea trials, 10 January 1955.", by U.S. Navy photo 80-G-709366, 1955, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Nucleic acid: "Friedrich Miescher's lab. Picture of the laboratory where Miescher isolated nuclein. The lab, a part of the University of Tübingen, was run by Felix Hoppe-Seyler, and located in the vaults of an old castle.", by Paul Sinner, 1879, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Nylon: "Control of nylon stockings at Malmö Strumpfabrik. A woman holds a sock against the light to examine the quality. Subjects: Work, Industry, Fashion, Textile", by Erik Liljeroth, 1954, licensed under CC BY 4.0, via Wikimedia Commons. View source. View in tree.
• Obsidian tool: "Echantillon d'obsidienne récolté près du Monte Pilato, dans l'île de Lipari (îles Eoliennes, Sicile). Dimensions : env. 3 cm.", by Ji-Elle It feels nice and warm It feels like a love storm, 2011, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Ocean thermal energy conversion: "French engineer Georges Claude (1870-1960) conducting a demonstration on ocean thermal energy conversion at the Institut de France in 1926.", by Agence de presse Meurisse, 1926, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Ocean thermal energy conversion plant: "OTEC in Hawaii.jpg", licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Octant: "Oktant.jpg", licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Odometer (China): "Stone rubbing of an ancient Chinese Han Dynasty odometer horse cart (汉代记里鼓车); the original relief came from the Xiao Tang Shan Tomb, c. 125 AD. Four musicians are seen seated in the cart and playing pan-pipes.", by An artist from the Han Dynasty, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Odometer (Western): "Vitruve's odometer, 1st century BC, Roma (reconstruction). Thessaloniki Technology Museum", by Gts-tg, 2017, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Offset printing: "manroland Druckmaschine für den Rollenoffset- und Zeitungsdruck", by Sven Teschke, 2007, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Oil lamp: "Oil lamp (exactly, deer fat lamp), found in Lascaux cave in Montignac, Dordogne, Aquitaine, France. Magdalenian culture, 17,000 BP. It can be viewed in the National Prehistory Museum in Les Eyzies-de-Tayac.", by Sémhur, 2009, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Oil refinery: "Ploesti, Romania. August 1, 1943. Oil storage tanks at the Columbia Aquila refinery burning after the raid of B-24 Liberator bombers of the United States Army Air Force. Some of the structures have been camouflaged", by United States. Office of War Information. Overseas Picture Division., 1943, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Oldowan stone tool: "Chopper: one of the earliest examples of stone industry. Original - private collection. Location: en:Melka Kunture, Ethiopia. Stage: Oldowan to 1.7 million years before our era. Size: 77x70x65 mm", by Didier Descouens, 2010, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• OLED: "diode électroluminescente organique ou DELO", by STRONGlk7, 2012, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Olive oil: "Ancient oil press, St. Peter's castle; Bodrum, Turkey", by Georges Jansoone (JoJan, 2007, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Ondes Martenot: "Les Ondes Martenot are an electronic music instrument invented in 1928 by Maurice Martenot at The Atelier Jean-Louis Martenot in Neuilly (near of Paris).", by 30rKs56MaE at Japanese Wikipedia, 2006, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Ondol: "온돌문화 (溫突文化) Ondol (Underfloor Heating)", by Cultural Heritage Administration, 2021, licensed under KOGL Type 1, via Wikimedia Commons. View source. View in tree.
• Open hearth furnace: "Regenerateur siemens nb.jpg", licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Opium poppy cultivation: "Opium crop from the Malwa region of India", by The original uploader was Deeptrivia at English Wikipedia., 2005, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Optacon: "Optacon II Reading Machine for the Blind", by DrBliss, 1983, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Optical amplifier: "A solitary laser beam cuts through the night sky. It streaks upwards from Unit Telescope 4 of ESO's Very Large Telescope, located at Paranal Observatory in Chile. The two Magellanic Clouds are visible to the left of the beam as faint, fuzzy patches against the starry background. The particularly bright star to the right of the beam is Canopus, the second brightest star in our night sky after Sirius. When ground-based telescopes view stars, the light they collect must travel through the layers of our atmosphere. The same water vapour, pollution, and turbulence that causes the stars in the sky to twinkle also result in blurred images— so in comes a technique known as adaptive optics. Adaptive optics systems use sophisticated deformable mirrors to counteract the negative effects of our atmosphere. The laser shines up into the sky, creating an artificial star about 90 kilometres from the ground.  Astronomers can then measure how this fake star twinkles in time, and can correct for this distortion. Telescopes that use adaptive optics can produce images sharper than those from space-based telescopes at certain wavelengths. A similar system is to be installed on the European Extremely Large Telescope (E-ELT). The E-ELT willhave six lasers, which will provide even higher-quality astronomical images over a much larger field-of-view — and provide more opportunities for striking snaps like this one. This image was taken on 4 March 2013 from the Visible and Infrared Survey Telescope for Astronomy (VISTA) platform by ESO photo ambassador Julien Girard, a staff astronomer at ESO. It was taken using a point and shoot compact camera which nowadays can perform night photography.", by ESO/J. Girard, 2014, licensed under CC BY 4.0, via Wikimedia Commons. View source. View in tree.
• Optical fiber: "Fibre optic strands", by BigRiz, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Oral polio vaccine: "Child receiving polio vaccine.", by USAID, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Orangery: "County Cork, Fota House-Orangery.", by Rosanne Donovan, 2018, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Organistrum: "Cropped version of the Image:Organistrumsantiago20060414.png", 2006, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Oscilloscope: "Sine wave with 10 kHz and a voltage of 70 microvolts (peak-peak), displayed on an analog oscilloscope Tektronix type 7613. At the upper rim of the screen, the user-set measurement parameters of the oscilloscope are displayed, which are 100 microseconds per grid unit (= distance between the lines etched into the screen) horizontally, and 20 microvolts per grid unit in vertical direction.", by Pittigrilli, 2014, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Oud: "Cropped image, from Riyad & Bayad, an Arabic tale.", by Maler der Geschichte von Bayâd und Riyâd, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Outrigger boat: "Ratak Islands sailing boats. From: Voyage pittoresque autour du monde", by Louis Choris (1795–1828), 0122, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Ox hide bellows: "line art drawing", by Pearson Scott Foresman, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Oxy-fuel welding and cutting: "Cutting torch.jpg", licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Oxygen (Scheele–Priestley): "Pneumatic trough, and other equipment, used by Joseph Priestley", by Joseph Priestley (1733-1804), 1775, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Oxygen (Sendigovius): "Alchemik Sedziwoj Matejko.JPG", by Jan Matejko, 1867, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Oxygen mask: "Early oxygen mask, from an article in Popular Science Monthly, January 1919, "How Aviators Get Oxygen at High Altitudes"", by Unknown authorUnknown author, 1919, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Oxyhydrogen blowpipe: "Blowpipe - circa 1827", by John Griffen, 1827, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Oyster farming: "Roman Drawing of an Ostraria", by Jean Victor Coste, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Ozone: "Structural formula of the ozone molecule, O3. O-O bond length of 127.8 pm (i.e. 1.278 Å) and O-O-O bond angle of 116.8° determined by microwave spectroscopy and taken from", by Д.Ильин: vectorization, 2024, licensed under CC0, via Wikimedia Commons. View source. View in tree.
• p–n junction: "a PN diode that display the electrical symbol associated with it. The triangle corresponds to the p side, while the other side is the n side", by Raffamaiden, 2012, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• p–n junction isolation: "PN Junction in Reverse Bias.png", licensed under GFDL 1.2, via Wikimedia Commons. View source. View in tree.
• Packet switching: "The block message as poposed by Paul Baran in 1964", by Michel Bakni, 2020, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Paddle wheel boat: "De Rebus Bellicis, XVth Century Miniature.JPG", licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Paddy field: "China; Handscroll; Paintings", by Unknown authorUnknown author, 1353, licensed under CC0, via Wikimedia Commons. View source. View in tree.
• Pager: "Swissphone RES.Q Hybrid POCSAG pager with GSM and GPS module", by Florian Fuchs, 2019, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• PageRank: "Numeric examples of PageRank values in a small graph with a damping factor of 0.85. The exact solution is: R = [ P R ( A ) P R ( B ) ⋮ P R ( K ) ] = 1 579662461 ⋅ ( 19002201 222822800 198772220 22657320 46886400 22657320 9372840 9372840 9372840 9372840 9372840 ) ≈ ( 0 , 03278149 0 , 38440095 0 , 34291029 0 , 03908709 0 , 08088569 0 , 03908709 0 , 01616948 0 , 01616948 0 , 01616948 0 , 01616948 0 , 01616948 ) {\displaystyle \mathbf {R} ={\begin{bmatrix}PR(A)\\PR(B)\\\vdots \\PR(K)\end{bmatrix}}={\dfrac {1}{579662461}}\cdot {\begin{pmatrix}19002201\\222822800\\198772220\\22657320\\46886400\\22657320\\9372840\\9372840\\9372840\\9372840\\9372840\end{pmatrix}}\approx {\begin{pmatrix}0,03278149\\0,38440095\\0,34291029\\0,03908709\\0,08088569\\0,03908709\\0,01616948\\0,01616948\\0,01616948\\0,01616948\\0,01616948\end{pmatrix}}} And here’s the solution for any arbitrary damping factor d: R d = [ P R d ( A ) P R d ( B ) ⋮ P R d ( K ) ] = ( 1 ( d + 1 ) ⋅ ( 7 d 4 + 28 d 2 + 12 d − 132 ) ) ⋅ [ ( d + 1 ) ( 7 d 3 + 6 d + 12 ) ( d − 1 ) − 9 d 3 − 18 d 2 − 46 d − 12 − 11 d 4 − 12 d − 12 − 18 d 3 − 32 d 2 2 ( d + 1 ) ( 7 d 2 + 2 d + 6 ) ( d − 1 ) 12 ( d + 1 ) ( 4 d 2 − 3 d − 1 ) 2 ( d + 1 ) ( 7 d 2 + 2 d + 6 ) ( d − 1 ) − 2 ( d + 1 ) ( − 6 + d 2 ) ( d − 1 ) − 2 ( d + 1 ) ( − 6 + d 2 ) ( d − 1 ) − 2 ( d + 1 ) ( − 6 + d 2 ) ( d − 1 ) − 2 ( d + 1 ) ( − 6 + d 2 ) ( d − 1 ) − 2 ( d + 1 ) ( − 6 + d 2 ) ( d − 1 ) ] {\displaystyle \mathbf {R_{d}} ={\begin{bmatrix}PR_{d}(A)\\PR_{d}(B)\\\vdots \\PR_{d}(K)\end{bmatrix}}=\left({\dfrac {1}{(d+1)\cdot (7\,d^{4}+28\,d^{2}+12\,d-132)}}\right)\cdot {\begin{bmatrix}\left({d}+1\right)\left(7\,{d}^{3}+6\,{d}+12\right)\left({d}-1\right)\\-9\,{d}^{3}-18\,{d}^{2}-46\,{d}-12\\-11\,{d}^{4}-12\,{d}-12-18\,{d}^{3}-32\,{d}^{2}\\2\,\left({d}+1\right)\left(7\,{d}^{2}+2\,{d}+6\right)\left({d}-1\right)\\12\,\left({d}+1\right)\left(4\,{d}^{2}-3\,{d}-1\right)\\2\,\left({d}+1\right)\left(7\,{d}^{2}+2\,{d}+6\right)\left({d}-1\right)\\-2\,\left({d}+1\right)\left(-6+{d}^{2}\right)\left({d}-1\right)\\-2\,\left({d}+1\right)\left(-6+{d}^{2}\right)\left({d}-1\right)\\-2\,\left({d}+1\right)\left(-6+{d}^{2}\right)\left({d}-1\right)\\-2\,\left({d}+1\right)\left(-6+{d}^{2}\right)\left({d}-1\right)\\-2\,\left({d}+1\right)\left(-6+{d}^{2}\right)\left({d}-1\right)\end{bmatrix}}}", by en:User:345Kai, User:Stannered, 2007, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Pan flute: "Pan pipes from South America. These pan pipes are probably not the best quality, but do play adequately. The pipes are made from bamboo and are tuned to a major scale, covering approximately 1.5 octaves. Keywords: Pan pipes, musical instrument, bamboo. :: (Note: although filename might be possibly inappropriate, source of derived image should be described. Also you can rename files using {{rename|Zampoña.jpg|3}}, where "3" means "Correct misleading names into accurate ones". See Commons:Rename for details.)", by Photograph © Andrew Dunn. Website: http://www.andrewdunnphoto.com/, 2005, licensed under CC BY-SA 1.0, via Wikimedia Commons. View source. View in tree.
• Panemone windmill: "This is a photo of a monument in Iran identified by the ID", by MorvaridiMeraj, 2017, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Pantelegraph: "Pantelegraph", by Giovanni Abbate Caselli, scanned by de:user:Wefo, 2009, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Paper: "Fragment of a paper map showing topographic features drawn in black ink, found on the chest of the occupant of Tomb 5 of Fangmatan, Gansu in 1986. The tomb dates to the early Western Han (i.e. early 2nd century BC). Size: 5.6 × 2.6 cm.", by Unknown authorUnknown author, 2012, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Paper cartridge: "Paper cartridges from Revolutionary War, 1775-1783 - Exhibit in the Old Colony History Museum - Taunton, Massachusetts, USA.", by Daderot, 2017, licensed under CC0, via Wikimedia Commons. View source. View in tree.
• Paper clip: "In "Editorial Miscellany", The Phonographic World, Vol. VIII.– No. 5, January 1893, 31 Broadway, New York City, E.N. Minder, editor, the editorial stated: " The Gem Paper Clip, advertised for the first time in the WORLD this month, and just placed on the markedt by Cushman & Denison, of New York, is one of the most useful contrivances we have ever seen. Be certain to read their advertisement." Searching this volume, I found two identical advertisements - this is one of them. The original may be viewed, here. https://hdl.handle.net/2027/mdp.39015011409193?urlappend=%3Bseq=485 The significance of this image is that it is a very early Gem Paper Clip advertisement - previously, the earliest one found by https://www.officemuseum.com/paper_clips.htm was Nov. 1893.", by Unknown authorUnknown author, 1893, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Paper machine: "A model of the original paper-making machined invented by Louis Robert in France in 1799. This was taken to England by John Gamble and patented in England. Henry and Sealy Fourdirinier bought one-third of the patent rights. It is hand-powered. The development to mechanical power, originally using a water-mill, was the work of Bryan Donkin. The model is in the museum of the Frogmore Paper Mill", by Chris55, 2021, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Paper money: "An illustration of a Chinese banknote from a paper about the monetary history of China written by John E. Sandrock.", by John E. Sandrock, 1300, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Paper recycling: ""From Waste Paper into War Weapons" - NARA - 514339.jpg", by Unknown authorUnknown author or not provided, 1941, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Papermaking: "An image of a Ming dynasty woodcut describing five major steps in ancient Chinese papermaking process as outlined by Cai Lun in 105 AD", licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Papyrus: "Papyrus.jpg", licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Parabolic antenna: "Replica of experimental microwave spark oscillator invented by Augusto Righi around 1894. These oscillators, connected to an induction coil, radiated radio waves with wavelengths less than 10 centimeters in the microwave band. The parabolic reflector focused the radiation into a beam. This type of spark oscillator, invented by Righi (which was based on previous studies by the scientists of Ginevra De la Rive and Sarazin) consisted of 4 brass spheres. The outer 2 were connected to the induction coil which applied a high voltage causing sparks between the spheres. The two inner spheres acted as resonators radiating the microwaves. The spark gaps were surrounded by a vaseline oil bath which decreased the energy losses. These oscillators were used with a receiver also equipped with a parabolic reflector (see attached photographic documentation and object number 8758). Righi used them to duplicate classical optics experiments with radio waves, using quasioptical components such as lenses and prisms of paraffin and sulfur and wire diffraction gratings to refract and diffract radio waves like light waves, to confirm the historic 1887 experiments of Heinrich Hertz, that radio waves and light waves were both forms of electromagnetic waves, differing only in frequency. Righi's oscillators also had great importance for the development of radio communications; in fact fellow Bolognese Guglielmo Marconi the inventor of practical radio in his first experiments in wireless telegraphy used a Righi type oscillator.", by Museo Nazionale della Scienza e della Tecnica "Leonardo da Vinci" (costruttore), 1984, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Parabolic radio telescope: "Amateur radio astronomer Grote Reber´s 9 meter (31.4 ft) parabolic radio telescope antenna, which he built in his backyard in Illinois in 1937. This was the second radio telescope ever built (after Karl Jansky's dipole array antenna), the first parabolic radio telescope and the first large parabolic dish, serving as the prototype for large dish radio telescopes built after World War 2. Its construction and the sky survey Reber did with it helped found the field of radio astronomy.", by Grote Reber, 1937, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Paracetamol: "Skeletal formula of paracetamol (N-(4-hydroxyphenyl)ethanamide, C8H9NO2).", by Benjah-bmm27, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Parachute: "N°. 4 – Descente de Jacques Garnerin en parachute (1797) Parachute jump by Jacques Garnerin · Fallschirmabsprung von Jacques Garnerin", by Created/published: Paris : Romanet & Cie., imp. edit.,, 1890, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Paraffin wax: "Prills of paraffin wax.", by Gmhofmann, 2011, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Parchment: "central European (Northern) type of finished parchment made of goatskin stretched on a wooden frame", by Michal Maňas, 2007, licensed under CC BY 2.5, via Wikimedia Commons. View source. View in tree.
• Parkesine: "Bébé en celluloïd", by Vassil, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Passarola: "The "Passarola", a primitive airship devised by Father Bartholomew Lawrence of Gusmão.", by Unknown authorUnknown author, 1709, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Pasteurization: "Industry during the First World War- Cheshire A female worker removes bottles of lager from the pasteurising tank at a Cheshire brewery in September 1918.", by Lewis, G P, 1918, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Patio process: "Depiction of the Hacienda Nueva de Fresnillo during silver reduction through the patio process. The Cerro de Proaño is visible in the background. Patio process: Low grade ore was crushed and ground into powder (through animal and human power), a mercury-silver mixture was created in which silver is chemically bound to mercury (the grey circles depicted in the painting), the rock and dirt particles were washed away and the evaporation of the mercury left the silver concentrate. The mine and processing plant were under the control of the Zacatecas State Government and Gualdi was presumably commissioned by the state.", by Pietro Gualdi, 1846, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Pattern-tracing lathe: "Harpers Ferry Armory gunsmith shop had machines for production of the lock, the stock and the barrel. The machines are from the 1850s and are all powered by water. The power is transmitted to the machine by a set of pulleys and leather belts. This machine is a Duplicating or Blanchard lathe used to create stock identical to a pattern.", by Jarek Tuszyński, 2015, licensed under CC BY 4.0, via Wikimedia Commons. View source. View in tree.
• Paul-Wyatt cotton mills: "Illustration from Lewis Paul's 1758 patent for a roller spinning machine", by Lewis Paul, 1758, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Paved roads: "Old Roman Road, leading from Jerusalem to Beit Gubrin, adjacent to regional hwy 375 in Israel", by Davidbena, 2018, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Payment card: "Logo of Diners Club International.", by Discover Financial, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Pedal bicycle: "Velocipede Michaux-1", by tetedelacourse, 2008, licensed under CC BY-SA 2.0, via Wikimedia Commons. View source. View in tree.
• Pelton wheel: "Pelton wheel from Walchensee, Germany hydro power station", licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Pendentive dome: "Saint Sophia, Constantinopolis", by Wilhelm Salzenberg (* 20. Januar 1803 in Münster; † 23. Oktober 1887 in Vernex-Montreux, Schweiz) Edited by Verlag von Ernst & Korn Berlin, 1854, 2021, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Pendulum clock: "One of the first pendulum clocks designed by Christiaan Huygens, and his treatise on the pendulum, Horologium Oscillatorium published in 1673, on display in Museum Boerhaave in Leiden, Netherlands. This may be Huygens's second pendulum clock, which was also finished in 1673 and is shown on the open page of the book. In it, Huygens demonstrated how to make the swing of the pendulum isochronous using "cycloidal" cheeks of metal (shown on page) to confine the suspension cord and give the pendulum a cycloidal trajectory. Huygens claimed an accuracy of 10 seconds per day.", by Rob Koopman (Flickr profile), 2009, licensed under CC BY-SA 1.0, via Wikimedia Commons. View source. View in tree.
• Pendulum physics: "Figura del libro di Galilei "Discorsi e dimostrazioni matematiche intorno a due nuove scienze"", by Galileo Galilei, 1638, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Penicillin: "Sample of penicillin mould presented by Alexander Fleming to Douglas Macleod, 1935. Front three-quarter view, grey background.", by Science Museum London / Science and Society Picture Library, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Penny-farthing: "Ordinary bicycle, Skoda Museum, Mlada Boleslav, Czech Republic", by Agnieszka Kwiecień (Nova), 2003, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Percussion cap: "British, London; Pair of revolving percussion pistols; Firearms-Pistols-Percussion", 1831, licensed under CC0, via Wikimedia Commons. View source. View in tree.
• Periodic table: "1869-periodic-table.jpg", by Dmitri Mendeleev, 1869, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Perspective in art: "Cappella brancacci, Guarigione dello storpio e resurrezione di Tabita (restaurato), Masolino.jpg", by Masolino da Panicale, 1424, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• PET-CT: "viewer medecine nucleaire keosys", by Mco44, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Petri dish: "Szalka petriego.jpg", licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Petroleum as fuel: "Crude oil = petroleum in a flask and a small beaker.", by Nefronus, 2020, licensed under CC0, via Wikimedia Commons. View source. View in tree.
• Petzval lens: "Petzval lens.", by Szőcs TamásTamasflex, 2009, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• pH: "A roll of universal indicator paper.", by Bordercolliez, 2011, licensed under CC0, via Wikimedia Commons. View source. View in tree.
• Phage display: "Phage display cycle. 1) fusion proteins for a viral coat protein + the gene to be evolved (typically an antibody fragment) are expressed in bacteriophage. 2) the library of phage are washed over an immobilised target. 3) the remaining high-affinity binders are used to infect bacteria. 4) the genes encoding the high-affinity binders are isolated. 5) those genes may have random mutations introduced and used to perform another round of evolution. The selection and amplification steps can be performed multiple times at greater stringency to isolate higher-affinity binders.", by Thomas Shafee, 2019, licensed under CC BY 4.0, via Wikimedia Commons. View source. View in tree.
• Phase array antenna: "First experimental phased array antenna, invented by Karl Ferdinand Braun in 1905 in Strasbourg, Germany. This was a 3 element array antenna which transmitted a beam of radio waves whose direction could be rotated electronically to 3 directions 120° apart. It consists of 3 monopole antennas at the corners of an equilateral triangle whose bisector is a quarter wavelength long. Two of the antennas are fed in phase but a quarter wave phase delay can be switched into the feed line of one. Braun won the Nobel Prize in Physics in 1909 for his radio work. Phased arrays are now widely used in radar and many other applications.", by Karl Ferdinand Braun, 1909, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Phase-contrast microscope: "phase contrast microscope", by GcG, 2007, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Phenakistiscope: "Phenakistoscope 3g07690u.jpg", licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Phoenician joint: "National Museum of Underwater Archaeology (ARQVA). On November 26, 2008, the new headquarters of the museum was inaugurated, designed by the renowned architect Guillermo Vázquez Consuegra, at the Alfonso XII dock in the city of Cartagena, after a long construction period filled with technical and financial difficulties. The museum preserves archaeological materials related to maritime trade in the Mediterranean, from the Phoenician era through the Punic, Hellenistic, and Roman periods. Its exhibition halls display collections of amphorae, used for transporting liquid materials, including Campanian and distinctly Roman types. Other exhibited materials include metallurgical objects, luxurious items such as ivory and glass, as well as inscriptions related to transportation. To complement the scientific and educational information, various charts are also displayed. The amphora is considered the primary container of this period and has become a key reference in underwater archaeological research, as its remains are widespread along the Mediterranean coast. Particularly notable are the remains of the two 7th-century BCE Phoenician ships found in Mazarrón, along with a significant portion of their cargo.", by santiago lopez-pastor from España, 2018, licensed under CC0, via Wikimedia Commons. View source. View in tree.
• Phonautograph: "1859 model of Édouard-Léon Scott de Martinville's phonautograph.", by Édouard-Léon Scott de Martinville (1817–1879), 1859, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Phonograph: "Thomas Edison and his early phonograph. Cropped from Library of Congress copy.", by Levin C. Handy (per http://hdl.loc.gov/loc.pnp/cwpbh.04326), 1877, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Phonograph cylinder: "Edison Cylinder Records with packages, from 1910 catalogue", licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Phonograph record: "German-American engineer Emile Berliner (1851-1929) with the model of the first phonograph machine which he invented.", by Unknown authorUnknown author, 1910, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Phosphorus: "Full title: The Alchymist, In Search of the Philosopher’s Stone, Discovers Phosphorus, and prays for the successful Conclusion of his operation, as was the custom of the Ancient Chymical Astrologers, by Joseph Wright of Derby, now in Derby Museum and Art Gallery, Derby, U.K.", by Joseph Wright of Derby, 1771, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Photographic camera: "The image shows the Susse Frères Daguerreotype camera from 1839, in exhibition in the Westlicht Photography Museum in Vienna, Austria. Two months before the public announce at the French Academy of Arts and Science of the process of Daguerreotype, Jacques Louis Mandé Daguerre signed a contract with his relative Alphonse Giroux and with the Maison Susse Frères to produce the cameras according to his instructions. Both cameras used the same lens produce by the Maison Charles Chevalier a lens f15 380 mm. Reference: http://image.eastmanhouse.org/taxonomy/term/289", by Liudmila & Nelson, 2010, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Photography: "Nicéphore Niépce’s “point de vue” heliograph, the oldest surviving photograph", by Nicéphore Niépce, 1827, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Photolithography: "A photomask", by Peellden, 2011, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Photomask projection aligner: "SÜSS MicroTec MA6 Mask Aligner. Photolithography 4/4 How to do ultraviolet photolithography in the clean room. RMIT MicroNanophysics Research Laboratory/MicroNano Research Facility. For the latest, see www.jamesfriend.net", by James Friend, 2012, licensed under CC BY 3.0, via Wikimedia Commons. View source. View in tree.
• Photomultiplier tube: "Dynodes.jpg", licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Photon and photoelectric effect: "Photoelectric effect in a solid: ultraviolet light ejects electrons from a crystal.", by Ponor, 2020, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Photonic-crystal fiber: "SEM micrographs of US Naval Research Laboratory-produced photonic-crystal fiber. (left) The diameter of the solid core at the center of the fiber is 5 µm, while (right) the diameter of the holes is 4 µm. Source: http://www.nrl.navy.mil/techtransfer/fs.php?fs_id=97", licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Photophone: "Illustration of the photophone's transmitter, originally from: El mundo físico : gravedad, gravitación, luz, calor, electricidad, magnetismo, etc. / A. Guillemin by: Guillemin, Amédée, published by: Barcelona Montaner y Simón, 1882", by Unknown authorUnknown author, 1880, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Photorefractive keratectomy: "SAN DIEGO (Feb. 17, 2010) Capt. David J. Tanzer, specialty leader of Navy Refractive Surgery and director of Refractive Surgery Program at Naval Medical Center San Diego, performs a photorefractive keratectomy (PRK) at Naval Training Center. PRK uses a laser to ablate the outer surface of the cornea. (U.S. Navy photo by Mass Communication Specialist 2nd Class Chad A. Bascom/Released)", by U.S. Navy photo by Mass Communication Specialist 2nd Class Chad A. Bascom, 2010, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Photostat: "Commercial Camera Company Photostat advertisement in Engineering News, volume 69, number 25, June 19, 1913, page 6.", by Commercial Camera Company, 1913, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Photovoltaic effect: "A solar panel in Marla, Cirque de Mafate, Réunion", by David Monniaux, 2005, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Physautotype: "Still life of a set table, by Joseph Nicéphore Niépce, 1824-1833, the second earliest known camera photograph of which any visual record has survived. It is seen here in a late 19th century printed reproduction. The original, which was on glass, disappeared very early in the 20th century and is presumed to have been accidentally destroyed; several conflicting accounts of its demise exist, including a suspiciously colorful one in which a mad scientist analyzing it went berserk and smashed it along with everything else in his laboratory.", by Joseph Nicéphore Niépce, 1825, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Piano: "1726 piano by Bartolomeo Cristofori, in the Musical Instrument Museum in Leipzig, Germany", by Opus33, 2015, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Piezoelectricity: "The Compensator could produce very small electric currents (in the region of picoamps) by exerting changing tensile forces on a crystal in the top of the equipment. This view shows the piezo crystal and the electrical connections to conduct the current. This type of apparatus was used in Pierre and Marie Curie's discovery of radium and polonium", by Dougsim, 2019, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Pigeon post: "Hans Hassenteufel, 19. Jh.: Junge Frau im orientalischer Kleidung mit Brieftaube Oil on canvas, 42 x 35,5 cm", by AnonymousUnknown author, 1850, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Pigments: "three different ochre- pigments", by Marco Almbauer, 2015, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Pike: "Alexander Mosaic, House of the Faun, Pompeii", by Unknown authorUnknown author, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Pine tar: "Author: PrzemekL A bottle containing wood tar. A souvenir from the village Losie in Poland. The main use of this substance is to treat skin problems.", by No machine-readable author provided. PrzemekL assumed (based on copyright claims)., 2005, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Pinfire cartridge: "Eley Brothers Pinfire Cartridge Box", by Aaron Newcomer, 2018, licensed under CC BY 4.0, via Wikimedia Commons. View source. View in tree.
• Pipa: "Cernuschi Museum 20060812 106.jpg", 2006, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Pipe organ: "From the Utrecht Psalter, man playing organ, a shepherd, and and angel.", by Unknown authorUnknown author, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Piston bellows: "Persian Method of Smelting Iron.", by William F. Durfee, 1890, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Pivoted scissors: "Illustrations of Forceps- Greek and Roman surgical instruments General Collections Keywords: surgical instruments- history; Greek World; Roman World; John Stewart Milnes", licensed under CC BY 4.0, via Wikimedia Commons. View source. View in tree.
• Placeholder zero: "Babylonian cuneiform digit 0.", by Dega180, 2011, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Planar process: "Annotated die photo of a Fairchild 74LS244 chip datecode 8314", by Robert.Baruch, 2017, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Planer: "Application of Motor Drive to a Planing Machine", by Andy Dingley (scanner), 1905, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Planetary theory: "Venus Tablet of Ammisaduqa. Neo-Assyrian period.", 2010, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Plasma display: "PLATO V Terminal with plasma display 1981 (Programmed Logic for Automated Teaching Operations), PLATO I was ~1960 the first generalized computer assisted instruction system", by Mtnman79 [1], 2008, licensed under CC BY 3.0, via Wikimedia Commons. View source. View in tree.
• Plasma globe: "A Plasma ball photographed from above. The 1/60s exposure is needed to capture the plasma filaments rather than blurring them to ribbons.", by Colin, 2013, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Plasma-enhanced chemical vapor deposition: "DC-PECVD system in action. DC plasma (violet) improves the growth conditions for carbon nanotubes in this chemical vapor deposition chamber. A heating element (red) provides the necessary substrate temperature.", by polyparadigm (talk · contribs), 2003, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Platinum: "Crystals of pure platinum grown by gas phase transport.", by Periodictableru, 2010, licensed under CC BY 3.0, via Wikimedia Commons. View source. View in tree.
• Player piano: "Original Pianola that was built by Edwin S. Votey being presented to Smithsonian Museum as gift.", by Unknown authorUnknown author, 1922, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Pleasure wheel: ""Увеселения женщин"", by Адам Олеарий / Adam Olearius, 1656, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Plumbing: "''", by Tjmhay at English Wikipedia, 2007, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Plutonium: "A weapons-grade ring of electrorefined plutonium, typical of the rings refined at Los Alamos and sent to Rocky Flats for fabrication. The ring has a purity of 99.96%, weighs 5.3 kg, and is approx 11 cm in diameter. It is enough plutonium for one bomb core. The ring shape helps with criticality safety (less concentrated material).", by Los Alamos National Laboratory, 1995, licensed under Attribution, via Wikimedia Commons. View source. View in tree.
• Plywood: "Finnish spruce plywood", by Bystander, 2009, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Pneumatic drill: "I took this photo. Pneumatic drill / jackhammer, with black en:silencer.", by Anthony Appleyard at English Wikipedia, 2006, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Pneumatic motor: "Victor_Tatin_aeroplane_1879", by Uploadalt, 1879, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Pneumatic tire: "Photo of the first pneumatic bicycle bicycle tyre produced by John Boyd Dunlop in the National Museum of Scotland, assumed object creation date: 1887", by Geni, 2016, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Pneumatic tube: "Washington, D.C. Miss Helen Ringwald works with the pneumatic tubes through which messages are sent to branches in other parts of the city for delivery", by Esther Bubley, 1943, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Pocket calculator: "microcifra 10、 HANIMEX 276 及び pocket-mini", by Windshear, 2015, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Pocket watch: "PHN - Watch 1505.jpeg", licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Pointed arch bridge: "An old bridge over Getar River in Yerevan, Armenia", by Yerevan History Museum, 1918, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Polished metal mirror: "Mirror of Pharaoh Nastasen (335-315 BC). Silver and copper. Nuri pyramid Nu 15. Sudan National Museum (SNM 1374).", by Tangopaso, 2022, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Polonium: "Polonium (Po) is # 84 on the Periodic Table of Elements. Forty-two isotopes of polonium are known - all are radioactive. Only one occurs naturally in trace amounts - polonium-210. This greenish sample is a uranium-bearing (U) mineral - one of the decay products of U is polonium-210. Info. at: en.wikipedia.org/wiki/Polonium and en.wikipedia.org/wiki/Isotopes_of_polonium", by James St. John, 2024, licensed under CC BY 2.0, via Wikimedia Commons. View source. View in tree.
• Polyester: "A close-up of a 100% Polyester shirt. I took this picture myself just moments ago.", by Damieng at en.wikipedia, 2004, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Polyethylene: "Polyethylene balls.", by Lluis tgn, 2011, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Polyimide: "Capton tape.", by Jérôme, 2007, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Polymerase chain reaction: "Photo of a strip of PCR tubes, each tube contains a 1000uL (1mL) reaction.", by Madprime, 2007, licensed under CC0, via Wikimedia Commons. View source. View in tree.
• Polyphonic synthesizer: "Hammond Novachord – front (small)", by Original uploader was Hollow Sun (talk) at en.wikipedia, 2009, licensed under CC BY 3.0, via Wikimedia Commons. View source. View in tree.
• Polystyrene: "Styropor bei ca. 200 fach mit Polfilter. Ausschnitt ca: 500µm x 500µm", by Jan Homann, 2006, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Polyurethane: "Prof. Otto Bayer in 1952 demonstrating his creation (from 1937), the polyurethane,.", by Bayer AG, 1952, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Population genetics: "Please report references to olei@despammed.com.", by Chiswick Chap, 2006, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Porcelain: "Verseuse phénix Musée Guimet 2418.jpg", by Vassil, 2008, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Portable audio player: "Original Sony Walkman TPS-L2 from 1979", by Binarysequence, 2015, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Portable defibrillator: "Pantridge statue, Lisburn (3) See 415240. This is the portable defibrillator.", by Albert Bridge, 2007, licensed under CC BY-SA 2.0, via Wikimedia Commons. View source. View in tree.
• Portable engine: "This image shows an old steam lokomobile. (specifically, a 'portable engine')", by André Karwath aka Aka, 2005, licensed under CC BY-SA 2.5, via Wikimedia Commons. View source. View in tree.
• Portland cement: "A pallet of Portland cement bags used for construction.", by KVDP, 2008, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Portolan chart: "A picture of the Carta Pisana, a map made at the end of the 13th century, about 1275-1300.", by Unknown authorUnknown author, 1275, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Positional decimal numerals and true zero: "Gwalior zeros", by Smith, David Eugene, 1860-1944, 1911, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Positional numeral system: "Multiplication table, on a tablet signed by an apprentice named Suen-apil-Urim. From Larsa, Old Babylonian period (ca. 1900-1600 BC). Ashmolean Museum 1924-447 https://cdli.ucla.edu/search/archival_view.php?ObjectID=P347486", by Zunkir, 2022, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Positron: "Cloud chamber photograph of the first positron ever observed. The thick horizontal line is a lead plate. The positron entered the cloud chamber in the lower left, was slowed down by the lead plane, and curved to the upper left. The curvature of the path is caused by an applied magnetic field that acts perpendicular to the image plane. The higher energy of the entering positron resulted in lower curvature of its path.Original caption: A 63 million volt positron (Hρ = 2.1×105 gauss-cm) passing through a 6 mm lead plate and emerging as a 23 million volt positron (Hρ = 7.5×104 gauss-cm). The length of this latter path is at least ten times greater than the possible length of a proton path of this curvature.", by Carl D. Anderson (1905–1991), 1932, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Positron emission tomography: "Positron emission tomography machine", by Spacecoastcreative, 2024, licensed under CC0, via Wikimedia Commons. View source. View in tree.
• Post windmill: "This is a photo of listed building number 1124265.", by DeFacto, 2017, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Postage stamp: "First world postal stamp ever issued : the Penny Black, Great Britain, 1840.", by General Post Office of the United Kingdom of Great Britain and Ireland, 1840, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Potassium: "Potassium pearls under paraffin oil. Original size of the largest pearl: 0.5 cm.", by Unknown authorUnknown author, licensed under CC BY 3.0, via Wikimedia Commons. View source. View in tree.
• Pottery: "Pottery bowl, 7100-5800 BCE, from Jarmo, Sulaymaniyah, Iraq. Sulaymaniyah Museum, Iraqi Kurdistan.", by Osama Shukir Muhammed Amin FRCP(Glasg), 2021, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Pound lock: "Drawing by William Alexander, draughtsman of the Macartney Embassy to China in 1793. A canal lock which the Embassy passed on November 6, 1793, during the travel from Han-tcheou-fou to Tchu-san. The drop of water was six foot; the water ended within one foot of the upper edge of the beam over which the flat-bottomed river boat had to be pushed. The lock consisted of a double glacis of sloping masonry, with an inclination of about forty degrees from the horizon. The pushing machinery was represented by two capstans in this particular lock, in other locks, four or six could be used. Alexander noted that canals were used as a preferred means of transportation and communication in the mountainous areas of China. Image taken from The Costume of China, illustrated in forty-eight coloured engravings, published in London in 1805.", by William Alexander, 1800, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Power loom: "Helmshore Mills Textile Museum. Camera location53° 41′ 20.4″ N, 2° 20′ 10.32″ W View this and other nearby images on: OpenStreetMap 53.689000; -2.336200 An early power loom made in Rochdale", by Clem Rutter, Rochester, Kent., 2011, licensed under CC BY 3.0, via Wikimedia Commons. View source. View in tree.
• Power MOSFET: "Cyril BUTTAY -- Two MOSFET in D2PAK package. These are 30-A, 120-V-rated each.", by No machine-readable author provided. CyrilB~commonswiki assumed (based on copyright claims)., 2006, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Power plug: "GEC Plug and Socket as illustrated in the 1893 GEC Catalogue", by General Electric, 1893, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Powered printing press: "Koenig's 1814 steam-powered printing press", by User:Parhamr, 2007, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Powered vacuum cleaner: "Early electric vacuum cleaner by Electric Suction Sweeper Company, circa 1908, predecessor of Hoover vacuum cleaner (1922). Exhibit in National Museum of American History, Washington, DC, USA.", by Daderot, 2011, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Praseodymium: "1.5 grams praseodymium under argon, 0.5 cm big pieces.", by Jurii, 2009, licensed under CC BY 3.0, via Wikimedia Commons. View source. View in tree.
• Praxinoscope: "Le praxinoscope à projection d'Émile Reynaud pour La Nature, revue des sciences - 1882, n° 492, page 357.", by Louis Poyet, 1882, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Pre-cut cardboard box: "Cardboard box. One of a series of common objects I photographed in the summer of 2005 to illustrate simple:Basic English picture wordlist. --agr 21:08, 3 August 2005 (UTC)", by ArnoldReinhold, 2005, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Precession of the equinoxes: "Precession of Earth's rotational axis due to the tidal force raised on Earth by the gravity of the Moon and Sun.", by NASA, Mysid, 2008, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Pressure cooker: "Papin's digester", 1680, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Pressure suit: "Photography of aviator Wiley Post in his third space suit.", licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Pressurized aircraft cabin: "Boeing 737NG fuselages on train flatcars, being shipped to the Boeing factory at Renton, Washington. Fuselage No. 3473 in the foreground became Boeing 737-800 MSN 35837, first flight November 8, 2010 and delivered to GOL Linhas Aéreas of Brazil on November 22, 2010 as 737-8EH registration PR-GUE.", by Dan Bennett from Seattle, USA, 2010, licensed under CC BY 2.0, via Wikimedia Commons. View source. View in tree.
• Printing press: "Tab. XXI c. Die Buchdruckerei. (Beschreibung lt. Quelle)", by Daniel Nikolaus Chodowiecki, 1770, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Programmable calculator: "La macchina, detta anche "perottina", presenta una parte posteriore compatta e uniforme in metallo, con le uniche disomogeneità corrispondenti a delle alette su un solo lato, alle due rientranze lungo lo spigolo superiore posteriore e alla prese di alimentazione posteriore. Nella parte anteriore, anch'essa compatta, sono visibili la stampante sequenziale a rullo integrata, in alto a sinistra, l'ingresso e l'uscita del dispositivo di lettura/registrazione per le cartoline magnetiche (il primo in alto, il secondo in basso, della zona centrale), un incavo con le spie "nascoste" di corretto funzionamento e di errore (verde, Correct Performance Light; rossa, Error Light), sul fronte alto a destra, e la tastiera a 37 tasti che comprende anche i tasti: di registrazione e di stampa del programma (Record Program Switch e Print Program Switch) con affianco il tasto di attivazione/blocco della tastiera (Keyboard Release Key) e di reset dei dati e delle istruzioni (General Reset Key), in alto davanti all'ingresso della cartolina magnetica; di reset dell'elettronica della tastiera (Clear Entry Key), in basso a destra della tastiera numerica. Inoltre, sul lato destro, sono visibili il tasto di accensione/ spegnimento (ON-OFF Key) e la manopola di impostazione della precisione decimale dei calcoli (Decimal Wheel). Caratteristiche tecnicheRAM: Linea di ritardo magnetostrittiva (1920 bit)Memoria di massa: Cartolina magnetica (1920 bit)Unità aritmetico logica: Elettronica a componenti discreti (transistor, diodi, resistori, ecc.) con architettura a micromoduliAzionamento: Manuale o automaticaTastiera: Ridotta, zero singolo, 37 tasti, integrata nella macchinaDispositivo di stampa: A impatto con rullo portacaratteri, 30 caratteri al secondo, integrato nella macchinaLinguaggio di programazione: Formato da 16 istruzioni: aritmetiche, trasferimento, stampa, salti condizionati e nonNote produttiveCapo progetto: P. G. PerottoDesign: M. BelliniProduzione: Dal 1965 Unità prodotte: 44.000 macchine (la maggior parte vendute negli Stati Uniti) Notizie storico-critiche Negli intenti di Roberto Olivetti (dal 1962 amministratore delegato del Gruppo Olivetti e direttamente responsabile del Laboratorio di Ricerche Elettroniche) e dei progettisti, capitanati dall'ing. Perotto, la Programma101 doveva essere di facile programmazione, poco costosa e "da scrivania". In quest'ottica, la scelta della memoria interna, portò ad adottare per la P101 una memoria di tipo magnetostrittiva o "a linea di ritardo" (Pulse Delay Line); tecnologia di tipo sequenziale, poco veloce e di limitata capacità rispetto alle memorie ai tempi in auge, come per esempio le memorie a nuclei di ferrite, che in confronto, però, erano ingombranti e costose. In particolare, ll dispositivo magnetostrittivo adottato sulla P101 memorizzava l'informazione come vibrazioni di tipo torsionale su un filo di acciaio armonico avvolto a formare una spirale cilindrica; per la trasformazione dei segnali elettrici, che portavano l'informazione, in vibrazioni meccaniche utilizzava un trasduttore posto ad un capo del filo, mentre per la trasformazione contraria adoperava un trasduttore complementare che riproduceva i segnali elettrici originali. Da qui i segnali venivano amplificati e ritornavano al primo trasduttore e il "circolo" ripartiva; tra la "partenza" dal primo trasduttore e l'arrivo al sencondo, l'informazione subiva un ritardo di circa 2,2 millisecondi, ciò permetteva la memorizzazione di circa 240 caratteri (da 8 bit ciascuno). La lettura dei dati avveniva sul secondo trasduttore, mentre la loro modifica avveniva nei circuiti elettronici tra il secondo e il primo trasduttore. Naturalmente la memoria si azzerava quando la macchina veniva spenta La funzione che svolgeva la memoria magnetostrittiva nella P101 era di memoria "cache", fondamentale per immagazzinare i risultati delle ultime operazioni e renderli velocemente accessibili alle successive istanze del programma; quindi, il ciclo di questa memoria, circa 2,2 millisecondi, sequenziava tutta l'unica rete logica che costituiva l'architettura della macchina: Memoria, Unità Aritmetica e di Controllo, Tastiera, Unità stampante di tipo seriale; e Dispositivo di lettura/registrazione per la cosiddetta "Cartolina magnetica". Tutta l'architettura si basava su tecnologia a transistor organizzati in "micromoduli" (circa 900 moduli elementari con complessivi 6.000 componenti). La tecnica dei micromoduli fu brevettata a nome di P.G. Perotto e di Eduardo Ecclesia (brevetto US 3.478.251) Per l'ingresso e l'uscita dei dati dalla macchina, ma anche per l'inserimento del programma e per la memorizzazione permanente di dati, fu scelta una tecnologia alquanto innovativa per i tempi: la "cartolina magnetica" (Magnetic Program Card). Si trattava di un tipo di memoria che precorreva il floppy disk; infatti, consisteva in una cartolina di materiale plastico flessibile con un lato rivestito di materiale magnetico su cui venivano memorizzati i dati. Poteva essere archiviata ed essere letta e/o modificata tramite il dispositivo, di lettura/registrazione, interno alla P101. La cartolina, quindi, costituiva una sorta di "memoria di massa" per la macchina con una capacità equivalente di circa 480 caratteri Il brevetto della P101, "Program Controlled Elettronic Computer", fu depositato nel 1965 a nome di P.G.Perotto e Giovanni De Sadre (brevetto US 3.495.222) Nel 1991 l'ing. Perotto ha ricevuto il premio Leonardo Da Vinci del Museo della Scienza e della Tecnica di Milano per le soluzioni tecnologiche adottate nella P101 e in particolare proprio per l'idea della cartolina magnetica Nella fase di industrializzazione, dopo un primo approccio dell'architetto Marco Zanuso, il design della carrozzeria definitiva fu affidato e realizzato dal giovane architetto Mario Bellini. Il design finale fu brevettato nel 1967 (brevetto USD 209.351).", by Olivetti (progettista/ costruttore), Bellini Mario (designer), Perotto Pier Giorgio (inventore/ progettista), 1965, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Programmable electronic computer: "A Colossus Mark 2 codebreaking computer being operated by Dorothy Du Boisson (left) and Elsie Booker (right), 1943", by Unknown authorUnknown author, 1943, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Programmable read-only memory: "ANT Nachrichtentechnik DBT-03 - Texas Instruments TBP18SA030N - 256 bit programmable read-only memory (PROM)", by Raimond Spekking, 2017, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Programmable synthesizer: "English: RCA Mark II Sound Synthesizer (designed by Herbert Belar and Harry Olson at RCA Victor)", by Rca mk2.jpg: Finnianhughes101 derivative work: RCA Mark II Sound Synthesizer.png: Clusternote derivative work: Clusternote (talk), 2008, licensed under CC0, via Wikimedia Commons. View source. View in tree.
• Proto-soap: "Ägypterinnen beim Fest und eine Dienerin", by Unknown authorUnknown author, 1450, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Proximity fuze: "This file is located here: http://www.wikihistory.navy.mil/pics/shell2.jpg archive link", by United States Navy, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Prussian blue: "The Pigment Prussian Blue was invented in 1706 and named after the country in which the invention took place.", by Saalebaer, 2012, licensed under CC0, via Wikimedia Commons. View source. View in tree.
• Psaltery: "Church San Maurizio today Museo della musica in Venice. Psaltery Venetian School 1700 - Of ancient oriental origin, after a period of scarcity, the psalter was in the midst of the sixteenth, seventh, and even European nineteenth century galleries.", by Didier Descouens, 2016, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Ptolemaic geocentrism: "Ptolemaic system. "Annotazione sopra la Lettione della Spera del Sacrobosco" Photo of the pages 90 and 91 with models of the ptolemaic system. From the ancient books collection of Mario Taddei", by Mauro Fiorentino, Theosebo, Phonasco, & Philopanareto., 1550, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Public bath: "This work is licensed under a Creative Commons License. The photo is available at http://www.world66.com/asia/southasia/pakistan/moenjodaro/lib/gallery/showimage?pic=/asia/southasia/pakistan/moenjodaro/moenjodaro. Archived at the Wayback Machine", by The original uploader was M.Imran at English Wikipedia., 2006, licensed under CC SA 1.0, via Wikimedia Commons. View source. View in tree.
• Public flush toilet: "Victorian urinals at the Windermere hotel at Windermere", by Northmetpit, 2012, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Public gas lighting: ""A Peep at the Gas-lights in Pall Mall", a humorous caricature of reactions to the installation of the new invention of gas-burning street lighting on Pall-Mall, London. Dialogue in caricature: Well-informed gentleman "The Coals being steam'd produces tar or paint for the outside of Houses -- the Smoke passing thro' water is deprived of substance and burns as you see." Irishman "Arragh honey, if this man bring fire thro water we shall soon have the Thames and the Liffey burnt down -- and all the pretty little herrings and whales burnt to cinders." Rustic bumpkin "Wauns, what a main pretty light it be: we have nothing like it in our Country." Quaker "Aye, Friend, but it is all Vanity: what is this to the Inward Light?" Shady Female "If this light is not put a stop to -- we must give up our business. We may as well shut up shop." Shady Male "True, my dear: not a dark corner to be got for love or money."", by Thomas Rowlandson, 1809, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Public-key cryptography: "Illustration of the Diffie–Hellman Key Exchange.", by Kristen Gilden, 2014, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Puddling: "Puddling furnace.jpg", licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Pulley: "Photo of two pulleys taken in the city of Kampen by user:GeeKaa", by GK Bloemsma, 2006, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Pulsejet: "Ramon Casanova and the pulsejet engine he constructed and patented in 1917", by Jcrbmc, 1917, licensed under CC BY 3.0, via Wikimedia Commons. View source. View in tree.
• Pump organ: "Walnut reed organ. John Church and Co, Cincinnati, Ohio. late 1800s.", by Boygold, 2012, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Punched card: "Close-up view of the punch cards used by Jacquard loom on display at the Museum of Science and Industry in Manchester, England. Photograph taken by George H. Williams in July, 2004.", by User Ghw on en.wikipedia, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Pyroelectricity: "Tourmaline Locality: Ambositra District, Amoron'i Mania Region, Fianarantsoa Province, Madagascar (Locality at mindat.org) Size: 57 mm × 47 mm × 3 mm (2.24 in × 1.85 in × 0.12 in) A spectacular slice from a large tourmaline with a cranberry red rind, bright pink just inside it, and yellowish-green center. It has been polished on both sides to a glassy luster.", by Robert M. Lavinsky, 2010, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Pythagorean theorem: "w:Plimpton 322, Babylonian tablet listing pythagorean triples", by photo author unknown, 1800, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Quadcopter camera drone: "A quadcopter camera drone in flight.", by Josh Sorenson, 2018, licensed under CC0, via Wikimedia Commons. View source. View in tree.
• Quadrant: "Ptolemy from "CLAVDIO TOLOMEO PRINCIPE DE GLI ASTROLOGI, ET DE GEOGRAFI" published by Giordano Ziletti", by Unknown authorUnknown author, 1564, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Quadruplex telegraph: "Identifier: CollectionUnitev1Edis (find matches) Title: Collection of United States patents granted to Thomas A. Edison, 1869-1884 Year: 1869 (1860s) Authors: Edison, Thomas A. (Thomas Alva), 1847-1931 Peters, N. (Norris), lithographer Hammer, William Joseph, 1858-1934, former owner. DSI Edison, Thomas A. (Thomas Alva), 1847-1931, inscriber. DSI United States. Patent Office Subjects: Catalogs Patents Edison, Thomas A. (Thomas Alva), 1847-1931 Inventions Telegraph Electric machinery Electric apparatus and appliances Phonograph Telephone Motors Catalogs Patents Catalogs Patents Catalogs Publisher: Washington, D.C. : U.S. Patent Office Contributing Library: Smithsonian Libraries Digitizing Sponsor: Smithsonian Libraries View Book Page: Book Viewer About This Book: Catalog Entry View All Images: All Images From Book Click here to view book online to see this illustration in context in a browseable online version of this book. Text Appearing Before Image: nner as is shown inmy application No. 156, filed October 14,1878. The incandescent conductor made in thismanner may be of any desired shape. I claim as my invention— 1. For electric lighting, a conductor of elec-tricity formed of finely-divided metal incor-porated with a non-conductor of electricity,substantially as set forth. 2. A rigid electric-light-giving body havinga longitudinal incision or separation from thebase to near the end, for insuring the circula-tion of the electric current through the entirebody, substantially as set forth. 3. In combination with a rigid light-givingbody having a longitudinal incision, an ex-pansive thermal-circuit regulator to control thestrength of the current by the heat developed,substantially as set forth. Signed by me this 3d day of December, A.D. 1878. THOMAS A. EDISON. Witnesses: Stockton L. Griffin,Geo. E. Carman. T. A. EDISON, Assignor of one-half interest to G. B. Prescott. Quadruplex-Telegraph Repeater.No. 8,906, Reissued Sept. 23, 1879. Text Appearing After Image: N_ PETERS. Photo-Lithographer. Wastwngtort, 0 C. United States Patent Office THOMAS A* EDISON, OF MEMO PARK, NEW JERSEY, ASSIGNOR OF ONE-HALF INTEREST TO GEORGE B. PRESOOTT. IMPROVEMENT IN QUADRUPLEX-TELEGRAPH REPEATERS. Specification forming part of Letters Patent No. 209,241, dated October 22, 1878; Keissue No. §,906. datedSeptember 23, 1879 ; application filed November 16, 1&78. To all ivliom lb may concern: Be it known that I, Thomas A. Edison,now of Menlo Park, in the county of Middle-sex and State of New Jersey, have inventedcertain new and useful Improvements in Quad -ruplex Telegraphs, which impro\ ements arefully set forth in the following specification,reference being had to the accompanying draw-ings. My present invention consists in certain im-provements upon the apparatus described inmy application for Letters Patent filed on orabout the 1st day of September, A. D. 1874,for improvement in duplex telegraphs, anddesignated as Case 99; and has for its object,first, to p Note About Images Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original work.", by Edison, Thomas A. (Thomas Alva), 1847-1931; Peters, N. (Norris), lithographer; Hammer, William Joseph, 1858-1934, former owner. DSI; Edison, Thomas A. (Thomas Alva), 1847-1931, inscriber. DSI; United States. Patent Office, 1869, licensed under No restrictions, via Wikimedia Commons. View source. View in tree.
• Quantum computer: "IBM Quantum System One in Ehningen, Germany.", by IBM Research, 2021, licensed under CC BY 2.0, via Wikimedia Commons. View source. View in tree.
• Quantum tunneling: "A (simplified) diagram of Quantum Tunneling, a phenomenon by which a particle may move through a barrier which would be impossible under classical mechanics.", by Cranberry, 2008, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Quark: "The quark structure of the proton. There are two up quarks in it and one down quark. The strong force is mediated by gluons (wavey). The strong force has three types of charges, the so-called red, green and the blue. Note that the choice of green for the down quark is arbitrary; the "color charge" is thought of as circulating among the three quarks.", by Arpad Horvath, 2006, licensed under CC BY-SA 2.5, via Wikimedia Commons. View source. View in tree.
• Quartz clock: "One of the first experimental quartz clocks, invented by physicist Warren Marrison around 1927 at Bell Telephone Laboratories. It keeps time with an electronic oscillator controlled by the quartz crystal under the dome vibrating at 100 kilohertz. The clock's signal is divided down in frequency by vacuum tube counters, and controls the synchronous electric clock on the front. The caption states it keeps time to better than one hundredth of a second per day", by Unknown authorUnknown author, 1931, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Quern-stone: "A "knobber quern" (disc quern with knob by which the upper-millstone is rotated) made of basalt stone from Palestine, which is typical of the Crusader and Mamluk period.", by Davidbena, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Quill: "Saint Ambrose by Rutilio di Lorenzo Manetti", by Pietro Rotari, 1650, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Quipu: "An Inca quipu, from the Larco Museum in Lima", by Claus Ableiter nur hochgeladen aus enWiki, 2007, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Rabbit pregnancy test: "Oryctolagus cuniculus, rabbit", by JM Ligero Loarte, 2013, licensed under CC BY 3.0, via Wikimedia Commons. View source. View in tree.
• Rabies vaccine: "A man receiving the rabies vaccine near his hip", by Unknown authorUnknown author, 1950, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Radar: "Antenna of one of the first experimental US radars being developed during the late 1930s on the roof of the US Naval Research Laboratory, Anacostia, Washington DC. Operating at 200 MHz, it was the first rotating radar antenna. Research in radiolocation was started as early as 1922 by Naval radio engineers Albert Hoyt Taylor and Leo Clifford Young. In 1930 at the newly opened NRL, with another engineer Lawrence Hyland they began a research program. In 1934 they patented a radar system. This picture shows a "bedspring" antenna made of multiple dipole antennas which was needed to create a beam narrow enough to locate ships or planes. The antenna is mounted on a mast so it can rotate and also tilt to point up into the sky. The rotating mast extends through the roof to a large manual wheel in the room below which contains the radar equipment, so it can be rotated by hand. Caption: Closeup of the antenna of the first complete radar, installed "topside" of a building at the Naval Research Laboratory, Anacostia, D. C. in the late 1930s. It is a "dirigible" antenna, meaning that it is so mounted that it can be turned to allow for around the compass search", by Unknown authorUnknown author, 1945, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Radial tire: "Exhibited at the NEC Birmingham Classic Car Show, November 15-17, 2013", by Andrew Bone from Weymouth, England, 2013, licensed under CC BY 2.0, via Wikimedia Commons. View source. View in tree.
• Radio broadcasting: "E-control room and radio studio located at the Finnish Broadcasting Company's premises on Fabianinkatu in 1938, the date of the photograph is estimated with a year's accuracy.", by Yle Arkisto - Yle Archives, 1938, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Radio control: "Telekino: receiver", by MdeVicente, 2011, licensed under CC0, via Wikimedia Commons. View source. View in tree.
• Radio waves: "Artist's conception of German scientist Heinrich Hertz historic discovery of radio waves in 1886. To generate the waves Hertz used a spark gap radio transmitter (rear) consisting of a spark gap between two brass balls attached to a half-wave dipole antenna consisting of two wires with metal plates at the ends, powered by a Ruhmkorff coil with primary current supplied by a set of liquid batteries on the lower table. The Ruhmkorff coil generated pulses of high voltage which caused sparks to jump between the brass balls. Each spark excited oscillating radio frequency currents in the antenna, which were radiated as electromagnetic waves (radio waves). For a receiver, Hertz used a simple loop of wire (in his hands) with a narrow gap between the ends, forming a narrow spark gap (this picture is slightly inaccurate; Hertz actually used a micrometer gap consisting of an adjustable thumbscrew with its end close to the opposite electrode, to precisely measure the spark length). The length of the wire was a quarter wavelength, so the loop formed a resonant loop antenna, and the radio waves excited a voltage in the wire. So each spark of the transmitter excited a spark in the receiver loop.", by File:Heinrich Hertz discovering radio waves.png: Unknown authorUnknown author derivative work: MikeRun, 1922, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Radioactivity: "Photographic plate made by Henri Becquerel showing effects of exposure to radioactivity.", by Henri Becquerel, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Radiocarbon dating: "The Temple Scroll (11Q20) - Google Art Project.jpg", by Unknown authorUnknown author, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Radiofax: "WGHF was a New York City radio station, which was used, using a subcarrier signal, to test the Finch broadcast facsimile system.", by None listed, 1945, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Radioimmunoassay: "Radioimmunoassay principle.", by Mikael Häggström, M.D. Author info - Reusing images- Conflicts of interest:  None Mikael Häggström, M.D., 2023, licensed under CC0, via Wikimedia Commons. View source. View in tree.
• Radioluminescent paint: "Radioluminescence. A 50's Radium Dial, previously exposed tu UV-A light", by Arma95, 2010, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Radium: "M. and Mme. Curie experimenting with radium", by André Castaigne, 1903, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Radon: "Cloud chamber with cloud tracks created by particles of ionising radiation. (Image taken after injection of radon.)", by Nuledo, 2016, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Raft: "Huckleberry Finn and Jim, on their raft, by E.W. Kemble from the 1884 edition. This is just a cropped version of Image:Huck-and-jim-on-raft.jpg", 1884, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Rail transport: "The Stockton and Darlington Railway opened in 1825.", by Unknown authorUnknown author, 1878, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Railway semaphore signal: "Castleton East Junction signal box 59 signal (Up Main Home 2, with R57 Up Main I.B. Home 1 Distant below). Sunday 8th June 2008", by David Ingham from Bury, Lancashire, England, 2008, licensed under CC BY-SA 2.0, via Wikimedia Commons. View source. View in tree.
• Rain gauge: "Jang Yeong-sil Science Garden in Busan commemorates the achievements of one of the greatest scientists of Joseon. The Rain Gauges are instruments to measure rain fall. The rain gauge is Treasure #842.", by Steve46814, 2013, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Ramjet: "Leduc 0.16 research ramjet aircraft at Musee de l'Air Le Bourget", by RuthAS, 2007, licensed under CC BY 3.0, via Wikimedia Commons. View source. View in tree.
• Rammed earth: "Pisé wall (rammed earth, not stabilized) in Nord-Isère, France, 2005", by Grégoire Paccoud, 2005, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Rapid transit: "Construction of the Metropolitan Railway, the world's first underground railway. Illustration shows the trench and partially completed cut and cover tunnel close to Kings Cross station, London. The railway opened in 1863.", by Percy William Justyne, 1861, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Rayon: "Un particolare ingrandito di una gonna in rayon.", by No machine-readable author provided. Digitalgadget~commonswiki assumed (based on copyright claims)., 2006, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Razor with protective guard: "Planche 2", by Jean-Jacques Perret, 1890, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Reading stone: "Reading stone in Archeon", by Ziko van Dijk, 2015, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Reaping machine: "Patrick Bell´s reaping machine, 1851", by George Heriot Swanston, 1851, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Rebab: "Rabel", licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Rebreather: "Photo of Henry Albert Fleuss", by not pointed, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Recombinant DNA: "gfd", by Minestrone Soup at English Wikipedia, 2007, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Recording telegraph: "Alexander Bain improved facsimile 1850", by European Patent Office, 1850, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Rectified linear unit: "A depiction of the Rectified Linear Unit (ReLU; max(0, x)) and the Gaussian Error Linear Unit (GELU; x * Phi(x)).", by Ringdongdang, 2020, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Recurrent neural network: "A Hopfield net with four nodes.", by Deditos, 2015, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Red phosphorus: "Red phosphor", by Tomihahndorf, 2006, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Reed pen: "Reed Pens", by Farzan44, 2016, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Reflecting telescope: "Replica of Newton's first reflecting telescope made in 1668 and now in the possession of the Royal Society of London. Made for the Science Museum in 1924 by Mr F.L. Agate", by The Science Museum UK, licensed under CC BY 4.0, via Wikimedia Commons. View source. View in tree.
• Reflective LLM: "Reflective agent architecture with self-reflection, evaluation, short/long-term memory, and environment interaction.", by Noah Shinn, Federico Cassano, Edward Berman, Ashwin Gopinath, Karthik Narasimhan, Shunyu Yao, 2023, licensed under CC BY 4.0, via Wikimedia Commons. View source. View in tree.
• Refrigerated ship: "Photograph of the "Dunedin", loading at Port Chalmers in 1882. The 1320 ton 73 metre Dunedin was built by Robert Duncan and Co at Port Glasgow in 1874 at a cost of ₤23,750. In 1881 she was refitted with a Bell Coleman refrigeration machine with which, in 1882 she took the first frozen load of meat from New Zealand to the United Kingdom. The photograph is of her loading at Port Chalmers in 1882. Although experimental voyages with refrigerated shipping had been made the previous year by Australian and American vessels, the Dunedin's trip was the first fully successful refrigerated shipment. The Dunedin continued in the frozen meat trade until she was lost without trace in 1890, en route from New Zealand to the UK - it is presumed she hit an iceberg off Cape Horn.", by The original uploader was Winstonwolfe at English Wikipedia., 1882, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Reinforced concrete: "This file was uploaded with Commonist.", by Lionel Allorge, 2013, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Reis telephone: "Johann Philipp Reis telephone", licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Reservoir: "Der große Hafir von Musawwarat fungiert jetzt als Tränke für die Tiere und Herden in der Region", by erdbeernaut, 2016, licensed under CC0, via Wikimedia Commons. View source. View in tree.
• Resonant inductive coupling: "Magnetic phase synchronus coupling", by Chetvorno, Discharger1016, 2017, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Respirator: "Humboldt's first gasmask", by Alexander von Humboldt, 1799, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Restriction enzymes: "GelDoc DNA gel electrophoresis photograph stained with ethidium bromide", by Sgroey, 2004, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Reusable spacecraft: "The Space Shuttle Discovery and its seven-member STS-120 crew head toward Earth-orbit and a scheduled link-up with the International Space Station. Liftoff from Kennedy Space Center's launch pad 39A occurred at 11:38:19 a.m. (EDT). Onboard are astronauts Pam Melroy, commander; George Zamka, pilot; Scott Parazynski, Stephanie Wilson, Doug Wheelock, European Space Agency's (ESA) Paolo Nespoli and Daniel Tani, all mission specialists.", by NASA; edited by jjron (tilt corrected), 2007, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Reverse osmosis: "I, Twhair, took this picture while on a tour of the North Cape Coral RO facility in 2006 while serving as a city councilmember.", by Twhair, 2006, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Reverse overshot water wheel: "Sequence of wheels found at Rio Tinto mines, Andalusia, Spain. Ancient Roman mine's drainage system.", by Peterlewis at English Wikipedia, 2008, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• RF CMOS: "This is a WiFi radio chip which was pulled from a WiFi card which was inside the same laptop as the Turion CPU I imaged earlier. This chip seems to be soldered to the metal plate which is present in most epoxy encased chips. I have not seen this before, normally thermal paste is used and I am able to detach this plate. This made the photography of this chip much more difficult due to the uneven surface on the back of this plate. The small black square in the bottom left region has inscriptions of the broadcom logo, "BCM2050A1", "2002", and a repeated sequence of "1" characters. I do not understand the purpose of the large circular structures, if anyone does please leave a comment below! Update: A friend of mine thinks they may be inductors, and after some searching online I am quite confident he is right. This is a composite of 54 images taken by a pixel 2XL from a microscope at 100X. The images had 65% overlap and were stitched together in Microsoft Image Composite Editor using the structured panorama mode.", by Cole L, 2020, licensed under CC BY-SA 2.0, via Wikimedia Commons. View source. View in tree.
• Rhinoplasty: "The Edwin Smith papyrus, the world's oldest surviving surgical document. Written in hieratic script in ancient Egypt around 1600 B.C., the text describes anatomical observations and the examination, diagnosis, treatment, and prognosis of 48 types of medical problems in exquisite detail. Among the treatments described are closing wounds with sutures, preventing and curing infection with honey and moldy bread, stopping bleeding with raw meat, and immobilization of head and spinal cord injuries. Translated in 1930, the document reveals the sophistication and practicality of ancient Egyptian medicine. Recto Column 6 (right) and 7 (left) of the papyrus, pictured here, discuss facial trauma. (Cases 12-20)", by Jeff Dahl, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Ribbon microphone: "BBC microphone-DEP 4574-IMG 7430-gradient edited.jpg", by Rama, 2018, licensed under CC BY-SA 3.0 fr, via Wikimedia Commons. View source. View in tree.
• Rifled musket: "Minie_rifle", by military postcard of 1870's, 1870, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Rifling: "This photograph was taken with an Olympus E-P5", by Petar Milošević, 2016, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Rimfire ammunition: "Vetterli cartridges", by Hmaag, 2011, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Roberts loom: "Illustration of power loom weaving.", by Illustrator T. Allom, Engraver J. Tingle, 1835, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Roberval balance: "Old two pan balance", by Nikodem Nijaki, 2011, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Robotaxi: "A Waymo-operated Jaguar I-Pace in San Francisco. The vehicle is operating autonomously without any person in the driver's seat.", by Dllu, 2023, licensed under CC BY 4.0, via Wikimedia Commons. View source. View in tree.
• Robotic vacuum cleaner: "An Electrolux Trilobite 2.0.", by Patrik Tschudin, 2006, licensed under CC BY 2.0, via Wikimedia Commons. View source. View in tree.
• Rochelle salt: "Potassium sodium tartrate, a double salt. Crystals in this bottle are tetrahydrate.", by ERS ROHU, 2023, licensed under CC BY 4.0, via Wikimedia Commons. View source. View in tree.
• Rock-cut stepwell: "Rani ki vav, Patan, India", by Bernard Gagnon, 2013, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Rocket: "The oldest depiction of rocket arrows. From the Huolongjing. The right arrow reads 'fire arrow,' the middle one is an 'arrow frame in the shape of a dragon,' and the left one is a 'complete fire arrow.'", by ed.: 焦玉 (Jiāo Yù and 文言 (w:Liu Bowen), 1350, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Roller skates: "Plimpton's roller skate prototype created between 1863 and 1866. A collection of the National Museum of Roller Skating, in Lincoln, Nebraska, USA. Wheeled skates of all types used to be briefly known as roller skates since 1860. But once Plimpton skates became popular worldwide, the term "roller skates" became synonymous with Plimpton's particular 2x2 wheel configuration. Later in the 1980s, skates with wheels in a single line became known as inline (roller) skate.", by Bruce McArthur DDS, 2019, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Rolling (metalworking): "Slitting mill", by John Mason Good, 1813, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Roman cement: "The South Door of Lichfield Cathedral Above the ornate doorway stand seven figures carved in Roman cement. Christ stands in the centre. On the right are Saint Chad, Saint James and John the Baptist. On the left are Saint Peter, Saint John and the Virgin Mary.", by Trevor Rickard, 2009, licensed under CC BY-SA 2.0, via Wikimedia Commons. View source. View in tree.
• Roman concrete: "Interior of the pantheon in Rome", by Jean-Christophe BENOIST, licensed under CC BY 2.5, via Wikimedia Commons. View source. View in tree.
• Rømer scale: "en:Ole Rømer (1644-1710), Danish astronomer.", by Jacob Coning, 1700, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Rope: "Hemp rope (4 strands with core, 150 meters, diameter 40mm, exhibited at the Corderie Royale of Rochefort, Charente-Maritime)", by Ji-Elle, 2009, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Rotary kiln: "Cement plant, Wyoming / 2008. Edit: Wyoming Lime Producers plant at 30 US-310, Frannie, WY 82423", by Greg Goebel from Loveland CO, USA, 2008, licensed under CC BY-SA 2.0, via Wikimedia Commons. View source. View in tree.
• Rotary printing press: "Richard March Hoe's printing press—six cylinder design", by Nathaniel Orr, 1864, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Rotary quern: "A "knobber quern" (disc quern with knob by which the upper-millstone is rotated) made of basalt stone from Palestine, which is typical of the Crusader and Mamluk period.", by Davidbena, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Rotary rocket: "William Hale's rotary rocket.", by Smithsonian Institution, 2013, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Rotoscoping: "Patent drawing for Fleischer's original rotoscope.", by Patent by Max Fleischer, artist Unknown authorUnknown author cropped/retouched by Rl, 1915, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Rowing oars: "Sets of traditional wooden oars", by Motmit, 2008, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Rubber: "A solid rubber ball used or similar to those used in the Mesoamerican ballgame, from Kaminaljuyu, 300 BC to 250 AD. With a manopla, or handstone, used to strike the ball, also from Kaminaljuyu, 900 BC to 250 AD. The ball is 3 inches (almost 8 cm) in diameter, a size that suggests it was used to play a hand ball. A mitten-shaped space has been carved out for the player's hand. The handstone was probably strapped in place. The far side of the stone is worn nearly smooth where it struck the ball, putting spin on it. Traces of rubber still adhere to the surface.", by Madman2001, 2007, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Ruhmkorff lamp: "Early portable electric lamp (ca. 1860) which science fiction author Jules Verne called the "Ruhmkorff lamp", but which was actually invented by Frenchmen Alphonse Dumas and Dr. Camille Benoît, for use by miners.", by Louis Laurent Simonin -- with Henry William Bristow, translator & editor (Life time: Louis L. Simonin: 1830-1886 ; H.W. Bristow: 1817-1889), 1869, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Rust-resistant iron: "Qutb Minar and its monuments, Delhi, INdia", by Diego Delso, 2009, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• S-trap: "Alexander Cummings S-bend flush toilet patent, 1775", by Alexander Cumming, 1775, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Saddle: "Exhibition: I am Ashurbanipal king of the world, king of Assyria, British Museum", by Carole Raddato from FRANKFURT, Germany, 2018, licensed under CC BY-SA 2.0, via Wikimedia Commons. View source. View in tree.
• Safety bicycle: "Rover safety bicycle of 1885 in the Science Museum (London)", by Jonathan Cardy, 2016, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Safety elevator: "Elisha Otis demo of his free-fall prevention mechanism, Crystal Palace, 1854.", by Unknown authorUnknown author, 2013, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Safety lamp: "This Clanny type safety lamp was badly damaged during the Abercarn Colliery explosion of 1878. The explosion killed 268 of the 325 men and boys working underground at the time. The lamp itself was only recovered from the workings in 1933.", by National Museum Wales, 2007, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Safety match: "Safety matches from Jönköping, often called Jönköpings Original. This label and earlier versions have been plagiarised many times.", by Agnat, 2020, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Safety pin: "Safety pin, patent 6281", by U.S. Patent Office - inventor Walter Hunt, 1849, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Safety razor: "Vintage Kampfe Bros. Star Single Edge Safety Razor, Made In USA, Circa 1900s", by Joe Haupt from USA, 2015, licensed under CC BY-SA 2.0, via Wikimedia Commons. View source. View in tree.
• Sail (Mediterranean): "Maler der Grabkammer des Menna 013.jpg", by Maler der Grabkammer des Menna, 1422, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Salmon farming: "Salmon farming cages in Torskefjorden, Torsken, Senja, Troms, Norway in 2014 August.", by Ximonic (Simo Räsänen), 2014, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Salt print: "The skills involved in producing calotypes were not only of a technical nature. Hill’s sociability, humour and his capacity to gauge the sitters’ characters all played a crucial part in his photography. He is shown here on the right, apparently sharing a drink and a joke with James Ballantine and Dr George Bell. Bell, in the middle, was one of the commissioners of the Poor Law of 1845, which reformed poor relief in Scotland, and author of Day and night in the wynds of Edinburgh[2]. Ballantine was a writer and stained-glass artist, and the son of an Edinburgh brewer. On the table we see a beer bottle and three 19th-century drinking glasses called “ale flutes”. One contemporary account describes a popular Edinburgh ale (Younger's) as "a potent fluid, which almost glued the lips of the drinker together, and of which few, therefore, could dispatch more than a bottle."[3]", by Hill & Adamson, 1844, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Saltpeter: "A sample of Potassium nitrate. Picture taken by w:User:Walkerma in June 2005.", by w:User:Walkerma, 2005, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Samarium: "Ultrapure sublimated samarium, 2 grams. Original size in cm: 0.8 x 1.5", by Unknown authorUnknown author, licensed under CC BY 3.0, via Wikimedia Commons. View source. View in tree.
• Samarium–cobalt magnet: "1980's vintage headphones utilising Samarium Cobalt magnets", by Colin99, 2014, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Sandal: "A pair of sandals from the Middle Neolithic.", 5200, licensed under CC BY 2.0, via Wikimedia Commons. View source. View in tree.
• Satellite navigation system: "Navigational satellite launched in the U.S. Navy Transit program, the I-B. Artwork by Roger Simmons. (9/15/15).", by National Museum of the U.S. Navy, 2015, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Saxophone: "Saxophone. (House of Monsieur Sax, Dinant).", by Thor19, 2015, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Scale armour: "From the cast of Trajan's column in the Victoria and Albert museum, London.", by No machine-readable author provided. Gaius Cornelius assumed (based on copyright claims)., 2005, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Scalpel: "Various scalpels / bistouries, both fixed blade and replaceable blade, from various manufacturers", by No machine-readable author provided. Spekta assumed (based on copyright claims)., 2006, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Schrödinger equation: "The Schrödinger equation.", by Erwin Schrödinger. Sander Bais. Gijs Mathijs Ontwerpers, Amsterdam, 2005, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Scientific pocket calculator: "HP 35", by MIC Torino (Russel2), 2013, licensed under CC BY 3.0, via Wikimedia Commons. View source. View in tree.
• Scintillation counter: "Schematic view of a photomultiplier coupled to a scintillator, illustrating detection of gamma rays", by This presentation was created with Microsoft PowerPoint., 2013, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Scramjet: "Diagram of principle of operation of a scramjet engine.", by Scramjet_operation.png: en:User:Emoscopes derivative work: Luke490 (talk), 2010, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Screw: "Drawing of a simple machine to demonstrate the action of a screw, from a 1912 scientific instrument catalog. It consists of a threaded shaft, threaded through a stationary mount. As the crank on the left is turned, the shaft moves axially through the hole.", by Unknown authorUnknown author, 1912, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Screw press: "Restored olive press in the Roman emperor", by שומבלע, licensed under CC BY-SA 2.5, via Wikimedia Commons. View source. View in tree.
• Screw-cutting lathe: "Photos of Henry Maudslay's famous screw-cutting lathes of circa 1797 and 1800. Although Maudslay did not invent any of the machine elements that went into the design, and although he did not invent the first screw-cutting lathe, he was the first person who made famous the winning form factor (bringing together the lathe, leadscrew, slide rest, and change gears, with practical inter-relationships.", by Unknown photographer, 1916, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Screwdriver: "Perfect Screwdriver set", by WayneRay, 2007, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Scroll: "Pic from Netherlands Wikipedia", by "Boekrol Esther 18de eeuw uit een sefardische synagoge in Sevilla" (Text from pic website), 2008, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Scuba set: "Diver on the wreck of the Aster, Hout Bay.", by Peter Southwood, 2010, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Scythe: "Rock engaving depicting scythes? and animal, Vingen, Norway. Wellcome Images Keywords: prehistoric art; Archaeology", licensed under CC BY 4.0, via Wikimedia Commons. View source. View in tree.
• Scythed chariot: "Alexander old drawings", by André Castaigne, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Seaplane: "Henri Fabre on Hydroplane 28 March 1910", by Anonymous, French Navy, 1910, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Search engine: "Screenshot of Archie", by The-Dubnob, 2004, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Seat belt: "Seatbelt testing apparatus.jpg", by National Institute of Standards and Technology, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Seaweed farming: "*Subject: Algae--Propagation Tag: Aquatic Botany", by Emile Wuitner, 1921, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Secondary emission: "With heavy overdrive on the phosphor tube.", by Rippey574, 2013, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Sector: "Brass sector with dividers, probably made in Dresden circa 1630, exhibited in the Mathematisch-Physikalischer Salon (Zwinger), Dresden, Germany. Four scales are visible on this sector; from inside to outside they are labeled "Lin. Arithmetica", an ordinary linear scale; "Lin. Stereometrica", a scale proportional to the cube root of its values, for working with volumes of solids; "Lin. Astronomica", some sort of scale involving trigonometric functions; and "Lin. Geometrica", a scale proportional to the square root of its values, for working with areas of plane figures. The dividers are positioned on the "Lin. Arithmetica" scale, marking the distance between corresponding marks, in roughly the way they would be held by someone using the sector. This artwork is old enough so that it is in the public domain. Photography was permitted in the museum without restriction.", by Daderot, 2013, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Seed drill: "Filling a feed-box in the drill working on the Canterbury Agricultural College farm in 1948.", by Ronald Charles Blackmore, 1948, licensed under CC BY 3.0, via Wikimedia Commons. View source. View in tree.
• Segmental arched bridge: "Roman Ponte Molino, Padua, Italy", by Gun Powder Ma, 2009, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Seismometer: "A replica of an ancient Chinese Seismograph from Eastern Han Dynasty (25-220 CE).This picture is taken from an exhibition at Chabot Space & Science Center in Oakland, California.The plaque of the exhibit said:Detecting a QuakeIn 132 CE, after several earthquakes in China, astronomer Zhang Heng invented this instrument to warn people of the next one. When the ground shook, it moved a pendulum inside the jug. The pendulum pushed a lever that opened one dragon's mouth. A ball rolled out and into the toad's mouth below, sounding an alarm. The open dragon mouth pointed in the direction of the earthquake, notifying the Emperor.", by en:user: Kowloonese, 2004, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Selective laser melting: "TRUMPF TruPrint 1000 is a metal 3D printer utilizing the selective laser melting (SLM) technology. View of the printing chamber with printing in progress. FZU – Institute of Physics of the Czech Academy of Sciences in Prague at Slovanka (Pod Vodárenskou věží 1), Department of Optical and Biophysical Systems in the Division of Optics.", by René Volfík, 2021, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Selective laser sintering: "w:en:DTM SLS-based rapid prototyping machine, Brazil. Author: en:Renato M.E. Sabbatini", by Rsabbatini at English Wikipedia, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Selective serotonin reuptake inhibitor: "Zimelidine 2D skeletal formula, originally from Zimelidine.png but converted into SVG. Also, the unknown stereoisomery has been changed into a double bond as per the structure of the compound.", by Zimelidine.png: User:Fuzzform / derivative work: Where next Columbus?, 2009, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Selenium: "Selenium in sandstone from New Mexico, USA. (SDSMT 3909, South Dakota School of Mines and Technology Museum of Geology, Rapid City, South Dakota, USA) A mineral is a naturally-occurring, solid, inorganic, crystalline substance having a fairly definite chemical composition and having fairly definite physical properties. At its simplest, a mineral is a naturally-occurring solid chemical. Currently, there are over 4900 named and described minerals - about 200 of them are common and about 20 of them are very common. Mineral classification is based on anion chemistry. Major categories of minerals are: elements, sulfides, oxides, halides, carbonates, sulfates, phosphates, and silicates. Elements are fundamental substances of matter - matter that is composed of the same types of atoms. At present, 118 elements are known (four of them are still unnamed). Of these, 98 occur naturally on Earth (hydrogen to californium). Most of these occur in rocks & minerals, although some occur in very small, trace amounts. Only some elements occur in their native elemental state as minerals. To find a native element in nature, it must be relatively non-reactive and there must be some concentration process. Metallic, semimetallic (metalloid), and nonmetallic elements are known in their native state. The rock shown above is from a "roll front deposit", in which native selenium occurs along a redox front in fluvial sandstone (see Granger & Santos, 1982). Stratigraphy & age of host rock: fluvial sandstone, Westwater Canyon Member, Morrison Formation, Upper Jurassic Locality; Section 23 Mine, Ambrosia Lake Mining District, north of Grants, New Mexico, USA Reference cited: Granger & Santos (1982) - Geology and ore deposits of the Section 23 Mine, Ambrosia Lake District, New Mexico. United States Geological Survey Open-File Report 82-207. 70 pp.", by James St. John, 2012, licensed under CC BY 2.0, via Wikimedia Commons. View source. View in tree.
• Selenium photocell: "密诺斯测光表 Minox selenium exposure meter", by 唐戈, 2005, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Self-acting hydraulic ram: "Lambach pump from Roscheider Hof open air museum, Konz, Germany", by HelgeRieder, 1998, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Self-acting spinning mule: "Roberts'_Self_Acting_Mule: Capture from Baines 1835, Illustrations from the History of the Cotton Manufacture in Great Britain .Pub H. Fisher, R. Fisher, and P. Jackson", by Baines, 1835, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Self-contained breathing apparatus: "Identifier: factoryindustria35newy (find matches) Title: Factory and industrial management Year: 1891 (1890s) Authors: Subjects: Engineering Factory management Industrial efficiency Publisher: New York (etc.) McGraw-Hill (etc.) Contributing Library: Engineering - University of Toronto Digitizing Sponsor: University of Toronto View Book Page: Book Viewer About This Book: Catalog Entry View All Images: All Images From Book Click here to view book online to see this illustration in context in a browseable online version of this book. Text Appearing Before Image: s invented anapparatus of which the earlier forms appeared in 1903 and the mostrecent in 1907. During these four years this respirator has proved:tself in many places, even as far as in Russia and Mexico. There are now two types of rescue apparatus in use in F-enchmines: I.—Portable appliances which permit the bearers to move at willthrough the mine galleries and upon which we shall dwell particularly. 2.—Apparatus with pumps and piping, having a much more lim-ited range of action, which are adapted for the prosecution of workrather than for rescue. The portable appliances in their turn may be divided into twoclasses: First, regenerative apparatus, and second, apparatus usingordinary air; these latter, although they give a more limited workingperiod than the former, appear to demand less nicety of manipulation.Furthermore, air exists everywhere, while at the moment of a disasteroxygen, potash, and other chemical necessaries may be lacking. In the RESCUE APPLIANCES IN FRENCH MINES. Text Appearing After Image: FIG. I. THE DRAEGER-GUGLIELMINETTI RESPIRATOR^ SEEN FROM BEHIND.Showing the oxygen reservoir, the pressure-reducer and the regenerator for exhaled gases. former class (much more largely employed in Germany and Austriathan in France) we may note particularly the ancient pneumatophores(Walcher, Mayer-Pilar, and Giersberg types) which generally con-sist of oxygen tanks delivering (usually without any regulator) intoan air-tight bag, from which the man inhales and into which he ex-hales. An absorbent, usually liquid, contained in this reservoir, puri-fies this air by the removal of the carbonic acid. They did not workvery well, and they have been abandoned, as has also the Shamrock 6 TUL ENGINEERING MAGAZINE. —an apparatus with a nKnith-piccc and a i)iiice-nez, having a pressurerccrnlator, a soWd ahsorhent inclosed in a cage within the air-tightsack, in whicii, also, circulation was mechanically maintained. The Draeger-Guglielminetti respirator merits larger notice, butIts mechanism is Note About Images Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original work.", by Internet Archive Book Images, 1891, licensed under No restrictions, via Wikimedia Commons. View source. View in tree.
• Self-propelled steam car: "Joseph Cugnot's 1770 Fardier à Vapeur, Musée des arts et métiers, Paris.", by Joe deSousa, 2015, licensed under CC0, via Wikimedia Commons. View source. View in tree.
• Self-propelled torpedo: "Withehead torpedo mecanism", by Louis Poyet, 1891, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Self-propelled wheelchair: "Self-propelled wheelchair of paralyzed watchmaker Stephan Farffler from 1655 built by him at the age of 22.", by Unknown authorUnknown author, 1730, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Semaphore telegraph: "Proposed: The representation of "B" has been edited to reflect its probable visual construction, whereas in previous images, including its original printing in Rees's "Cyclopaedia" (1802-1820), the "B" has been printed identical to the "S" representation.", by Morgan Riley, Patrick87, 2015, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Semi-automatic pistol: "Cased Borchardt Pistol", by Hmaag, 2015, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Semi-automatic shotgun: "American gunmaker John Moses Browning with with his Auto 5 shotgun (circa early 1900).", by Unknown authorUnknown author, 1900, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Semiconductors: "Chunk of ultrapure silicon, 2 x 2 cm.", by Jurii, 2009, licensed under CC BY 3.0, via Wikimedia Commons. View source. View in tree.
• Seq2seq: "Illustration for RNN with encoder and decoder.", by Daniel Voigt Godoy, 2021, licensed under CC BY 4.0, via Wikimedia Commons. View source. View in tree.
• Sericulture: "Cropped from Sericulture, The Process of Making Silk (蚕织图), a Chinese Song dynasty painting attributed to Liang Kai (梁楷).", by Attributed to Liang Kai, 1250, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Sewing machine: "The first sewing machine, invented by Thomas Saint, London, 1790; illustration from Lewis Lyons et al (c. 1926), The Sewing Machine: An Historical and Practical Exposition, London: John Williamson Co. Ltd., page 1.", by Unknown photographer, 1926, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Sewing needle: "Flat bone sewing needle - Views of the same object Locality : Gourdan cave says "Elephant Cave", Gourdan–Polignan, Haute-Garonne , France Search and collection: Henri Filhol Stage : Magdalenian Upper Paleolithic (between 17,000 and 10,000 Before the Current Era) Size : 59x3x2 mm", by Didier Descouens, 2010, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Sewn boat building: "Solar bark of Kheops. Detail. Image taken by Alex Lbh in April 2005.", by No machine-readable author provided. Bradipus assumed (based on copyright claims)., 2005, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Sextant: "Sextant.jpg", licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Shaduf: "Scene of gardener using a Shaduf, Tomb of Ipuy at Deir-el-Medina, West bank of Thebes, TT217.", by Norman de Garis Davies, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Sheng: "Chinese; Sheng; Aerophone-Free Reed-mouth organ", 1850, licensed under CC0, via Wikimedia Commons. View source. View in tree.
• Ship of the line: "The English warship Prince Royal with Frederick V of the Palatinate and his consort Elisabeth of England on board, arriving at Vlissingen in Holland in 1613. Detail of an oil painting fråm 1623 by the Dutch artist Hendrick Cornelisz Vroom. Frans Hals Museum.", by Hendrick Cornelisz Vroom (1562/1563–1640), 1623, licensed under CC0, via Wikimedia Commons. View source. View in tree.
• Shoe: "As of 2010, the oldest known leather shoe, recovered at the base of a Chalcolithic pit in the cave of Areni-1, Vayots Dzor, Armenia.", by Pinhasi R, Gasparian B, Areshian G, Zardaryan D, Smith A, et al. (authors of source article), 2010, licensed under CC BY 2.5, via Wikimedia Commons. View source. View in tree.
• Shukhov cracking process: "The Factory of Shukhov cracking process by the great Russian engineer and scientist Vladimir Shukhov (1853-1939) in 1934.", by Unknown authorUnknown author, 1934, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Sickle: "Rekonstruktion einer jungsteinzeitlichen Sichel im Neandertthal-Museum (Original 5.900 - 5.500 Jahre alt), Weißdornholz mit Feuersteinklingen", by Ökologix, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Siemens–Martin process: "Siemensmartin12nb.jpg", licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Signal lamp: "USS Mason (DE-529). Signalman Second Class Julius Holmes receives Signal lamp instruction from SM1c Ernest V. Alderman (left), during training for Mason's crew at the Norfolk Naval Training Station, Virginia, 3 January 1944. Original caption: "Photo # 80-G-214545 USS Mason crewman receives signal lamp trainig"", by Unknown (Official U.S. Navy Photograph, now in the collections of the National Archives.), 1944, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Sildenafil: "Viagra tablet.", by Kehkasha, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Silica gel: "Silica gel beads sparkling in light", by Wiebew, 2006, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Silicon: "Close up photo of a piece of purified silicon.", by Enricoros at English Wikipedia, 2007, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Silicon carbide: "Crystal (synthetic) Carborundum, or Carborundum (registered trademark) or "artificial Moissanite" ( silicon carbide); thermally stable material, very hard and chemically inert, accidentally discovered in 1824 by Jöns Jacob Berzelius while trying to synthesize diamond. the mineralogy collection Lille Museum", by Lamiot, 2016, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Silicon carbide JFET: "Schematic cross sections of silicon carbide unipolar switches", by Igor Vladimirovich Ivanov, 2018, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Silicon steel: "Grain-oriented electrical steel without coating showing the polycrystalline structure. The photo is taken with a regular digital camera. The size of the image is 6.0 x 4.8 cm.", by Zureks, 2007, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Silicone: "Silicone caulking extruded from a caulking gun", by Achim Hering, 2007, licensed under CC BY 3.0, via Wikimedia Commons. View source. View in tree.
• Silk: "Meister nach Chang Hsüan 001.jpg", by Meister nach Chang Hsüan, 1150, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Silver: "A pure (>99.95%) silver crystal, synthetic electrolytic made with visible dendritic structures. Weight ≈11g. this image was made from 12 single pictures via focus stacking", by Alchemist-hp (talk) (www.pse-mendelejew.de), 2009, licensed under CC BY-SA 3.0 de, via Wikimedia Commons. View source. View in tree.
• Silver mirror: "Mirrors: a work table and equipment for silvering glass. Engraving by Benard after Bourgeois. Iconographic Collections Keywords: Bourgeois; Robert Bénard", licensed under CC BY 4.0, via Wikimedia Commons. View source. View in tree.
• Silver nitrate: "Silver nitrate crystals", by W. Oelen, 2005, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Simple suspension bridge (Old World): "Plate 23 from the fourth set of 'Oriental Scenery.'<br Rope bridge across, Alakananda River, Srinagar, Garhwal, 1784-94, when Thomas and William Daniell reached Srinagar, the then Raja of Srinagar was involved in a war with his brother, they were advised to leave the town, which they did using the rope bridge across the river which was in spate, probably due to the Rainy season in the area, which July-September.", by Thomas Daniell, 1805, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Sine quadrant: "sine-cosine quadrant with arcs of sine and versed sine", by Khalili Collections, 2013, licensed under CC BY-SA 3.0 igo, via Wikimedia Commons. View source. View in tree.
• Siphon: "A Pythagorean cup (also known as a Pythagoras cup, a Greedy Cup or a Tantalus cup) is a form of drinking cup which forces its user to imbibe only in moderation. Credited to Pythagoras of Samos, it allows the user to fill the cup with wine up to a certain level. If the user fills the cup only up to that level he may enjoy his drink in peace. If he exhibits gluttony, however, the cup spills its contents out the bottom (the intention being: onto the lap of the immodest drinker).", by Nevit Dilmen (talk), 2012, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Skyscraper: "Exterior of the Home Insurance Building by architect William Le Baron Jenney in Chicago, Illinois.", by Chicago Architectural Photographing Company, 1884, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Slide projector: "Continuous-Slide Lantern. Precursor to the slide projectioner.", by Sloane, T. O'Conor., 1895, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Smallpox vaccine: "Dr Jenner performing his first vaccination on James Phipps, a boy of age 8. May 14th, 1796.", by Ernest Board, 1910, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Smart speaker: "Alexa Amazon Credit <a href="http://www.quotecatalog.com" rel="noreferrer nofollow">www.quotecatalog.com</a> with an active link required. Image is free for usage on websites (even websites with ads) if you credit <a href="http://www.quotecatalog.com" rel="noreferrer nofollow">www.quotecatalog.com</a> with an active link.", by Stock Catalog, 2018, licensed under CC BY 2.0, via Wikimedia Commons. View source. View in tree.
• Smartphone: "The IBM Simon Personal Communicator and charging base", by Bcos47, 2012, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Smoke helmet: "Charles Dean's Apparatus for Extinguishing Fires, 1825.", by Samuel Bellin, 2013, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Smokeless gunpowder: "Vihtavuori N110 smokeless gunpowder", by Halen, 2006, licensed under CC BY-SA 2.5, via Wikimedia Commons. View source. View in tree.
• Smokeless powder cartridge: "8mm Lebel - 8 mm Cartouche mle 1886D Origin: France Manufaturer: Atelier de Construction de Tarbesmetal supplied by Castelsarazin Solid bronze bullet", by Jim Miles, 2018, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• SMS: "SMS message received on a Motorola RAZR wireless handset. Note the "New Message" dialogue at the top, telling the user that a new message has just arrived, and the two soft menu buttons at the bottom corners suggesting actions to take. The text contains a variation of the sample "The quick brown fox jumps over the lazy dog", written as "The Quick Red Fox Jumped Over The Lazy Dogs."", by Scared Poet (user Scaredpoet, scaredpoet.com), 2007, licensed under CC BY-SA 2.5, via Wikimedia Commons. View source. View in tree.
• Snaphance: "Snaphaunce guns of national Swedish type, middle of 17th century.", 1927, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Snaplock: "Snaphaunce type of flintlock generating sparks", by Trulock, 2012, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Snow goggles: "An inuit wearing snow goggles", by Julian Idrobo from Winnipeg, Canada, 2007, licensed under CC BY-SA 2.0, via Wikimedia Commons. View source. View in tree.
• Snowmobile: "This is a late wood bodied Bombardier B-12 snow bus. Wood bodied Bombardiers were built until approximately 1951 or perhaps 1952 when production switched to metal bodies.", by Melensdad at English Wikipedia, 2007, licensed under CC BY 2.5, via Wikimedia Commons. View source. View in tree.
• Soap: "This file was uploaded with Commonist.", by Lionel Allorge, 2015, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Social network service: "The logo of SixDegrees.com – social network service", by Six Degrees, 2019, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Sodium: "Sodium (Na) metal from the Dennis S.K. collection. Selfmade photo.", by The original uploader was Dnn87 at English Wikipedia., 2007, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Sodium–sulfur battery: "Cut-away schematic of Sodium-sulfur battery.", by Original = NASA John Glenn Research Center, Vector: Sandra Hanbo, 2022, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Software as a service: "See title", by Ted Goldman, 2024, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Solar calendar: "Calendar in the temple of Kom Ombo. The calendar shows the hieroglyphics for the days of the fourth month of the harvest and the first day of the first month of the flood (scroll over for translation). The hieroglyph Peht on 30 Mes. indicates the end of the harvest season. The five epagomenal days are not listed.", by Ad Meskens, 2011, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Solar calendar with leap years: "Sousse Museum in the Medina", by Yamen, 2021, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Solar cell: "Explorer 6 paddles up.jpg", licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Solar cooker: "A parabolic solar cooker with a reflective metallic dish focusing sunlight to a central point. It's supported by a metal frame. Set outdoors on a sunny day.", by Solarbroman, 2024, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Solar furnace: "Four solaire de Mont-Louis", by Xaviateur, 2009, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Solar sail: "The Japanese IKAROS spaceprobe in flight (artist's depiction).", by Andrzej Mirecki, 2011, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Solar thermal power station : "solar thermal thermosyphon water heater photographed on the roof of a house", by Cachogaray, 2010, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Solid-state drive: "SSD drive Patriot P210 2TB", by Jacek Halicki, 2023, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Soluble cellulose acetate: "Here is depicted a piece of ILFORD HP5 safety film after it had been digitally converted into a positive image. That shot was taken free hand with a 1.8/105 mm objective in an available light situation.", by T.Voekler, 2008, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Sound film: "Description: Low-resolution image of poster for 1902 en:Gaumont en:sound film exhibition Original rights holder: Gaumont Source: Galerie d'affiches: 1900-1910 Public domain explanation The image was published in France as an anonymously designed business advertisement over 70 years ago. There is no evidence that the image has ever been published with the artist's or artists' names and a copyright claim.", by L. Gaumont & Co, 1908, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Sous vide: "Two PolyScience Sous Vide Immersion Circulators cooking Eggs on the left and meat inside vacuum bags on the right", by Pedro.serna, 2011, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• South-pointing chariot: "Model of a Chinese South Pointing Chariot, an early navigational device using a differential gear.", by Andy Dingley, 2008, licensed under CC BY 3.0, via Wikimedia Commons. View source. View in tree.
• Soxhlets extractor: "Киевский университет им. Т. Шевченко. Лаборатория химии природных соединений. Экстракторы", by Аимаина хикари, 2013, licensed under CC0, via Wikimedia Commons. View source. View in tree.
• Soybean paste and soy sauce: "Soy sauce", by 국립국어원, 2010, licensed under CC BY-SA 2.0 kr, via Wikimedia Commons. View source. View in tree.
• Space blanket: "emergency blanket", by No machine-readable author provided. Firetwister assumed (based on copyright claims)., 2005, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Space capsule: "The uncrewed SpaceX Crew Dragon spacecraft is the first Commercial Crew vehicle to visit the International Space Station. Here it is pictured with its nose cone open revealing its docking mechanism while approaching the station's Harmony module. The Crew Dragon would automatically dock moments later to the international docking adapter attached to the forward end of Harmony. (cropped and brightened from the original)", by NASA, 2019, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Space station: "USSR stamp: Cosmonauts Georgy Dobrovolsky, Vladislav Volkov and Viktor Patsayev. Series: In Memory of Cosmonauts, Who Died During the "Soyuz 11" Space Mission, June 6-30, 1971", by USSR Post, 1971, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Space suit: "Capsule and space suit of Yuri Gagarin, first man in space, at the Memorial Museum of Astronautics in Moscow", by greenacre8, 2011, licensed under CC BY 2.0, via Wikimedia Commons. View source. View in tree.
• Space telescope: "Orbiting Astronomical Observatory.jpg", licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Spandex: "A young male cyclist wearing a WTOS Delft summer cycling kit, front view.", by Adenosine Triphosphate, 2022, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Spar torpedo: "19th_century_Spar_torpedo_boat. Very similar in appearance to the boat filmed by G.West and Sons in around 1897 for which there is extant moving film available. See also: Our Navy Website - 'Extant Films' section.", by Unknown authorUnknown author, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Spear: "Detail of Clacton Spear 01 The Clacton Spear, display at the National History Museum. London. Sign reads: "The Clacton spear Made of yew, this spear point is the oldest preserved wooden spear in the world, Its owner would probably have used this as a lethal weapon, stabbing prey at close range to generate enough force to pierce the animal's skin. Taxus sp. Clacton, Essex, England, around 420,000 years old. E1138"", by Chemical Engineer, 2016, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Spear-thrower: "Nativo do Novo Mundo lançando flecha com o propulsor ou estólica.", by Sebastião da Silva Vieira, 2014, licensed under CC BY 3.0, via Wikimedia Commons. View source. View in tree.
• Special relativity: "SVG version of World line.png", by SVG version: K. Aainsqatsi at en.wikipedia Original PNG version: Stib at en.wikipedia, 2007, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Spectrophotometer: "Diagram of the Model DU Spectrophotometer, showing Mounting Block, Cell Compartment, Phototube Housing and Lamp Housing detached from the Monochromator.", by Unknown authorUnknown author, 1947, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Speculum metal mirror: "Photo for the first speculum metal mirror made for William Herschel's 40-foot telescope on display in the science museum.", by user:geni, 2008, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Speech recognition software: "Grafik als Beispiel für eine kontinuierliche Phrase", by Benutzer:Mwka, 2004, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Speed of light: "A diagram of Jupiter (B) eclipsing its moon Io (DC) as viewed from different points in earth's orbit around the sun. From Olaf (Ole) Roemer, "Demonstration tovchant le mouvement de la lumiere trouvé par M. Römer de l' Academie Royale des Sciences," December 7, 1676. Translated into English as "A Demonstration Concerning the Motion of Light," Philosophical Transactions of the Royal Society 12 (June 25, 1677): 893-94. Scans of both the French and English versions of the paper are on the Web at http://dbhs.wvusd.k12.ca.us/webdocs/Chem-History/Roemer-1677/Roemer-1677.html. This image was scanned from a copy of Roemer's paper in William Francis Magie, A Source Book in Physics, 1st ed (New York, London: McGraw-Hill, 1935).", by Ole Rømer, 1676, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Spermaceti and sperm oil: "A bottle and can of sperm oil on display in the New Bedford Whaling Museum (Massachusetts, USA).", by Raphael D. Mazor, 2007, licensed under CC BY 2.0, via Wikimedia Commons. View source. View in tree.
• Sphericity of the Earth: "John Gower world Vox Clamantis detail.jpg", licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Spinning jenny: "A Spinning Jenny, spinning machine which initiated the Industrial Revolution, model at the Museum of Early Industrialisation in Wuppertal (Germany).", by Markus Schweiß, 2004, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Spinning mule: "The introduction of the Spinning Mule into cotton production processes helped to drastically increase industry consumption of cotton. This example is the only one in existence made by the inventor Samuel Crompton. It can be found in the collection of Bolton Museum and Archive Service.", by Pezzab, 2007, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Spinning wheel: "Illustration of al-Hariri Maqamat spinning wheel.jpg", licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Spiral stairs: "Temple A in Selinunte.Detail: Remains of spiral stair between pronaos and cella", by Robert Koldewey (1855-1925), 1899, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Spirit level: "Detalle Nivel de Burbuja", by aTarom, 2004, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Sponge: "Natural sponges on sale in Kalymnos, Greece.", by kallerna, 2012, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Spreadsheet: "Screenshot of VisiCalc running on an Apple II computer", by User:Gortu, 2005, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Sprengel pump: "Drawing of a Sprengel mercury vacuum pump, invented in 1865 by German chemist Hermann Sprengel. It was capable of evacuating containers to 10-6 atmosphere. It was used by William Crookes to investigate cathode rays, by William Ramsay to isolate the noble gases, and was the key technology that enabled Joseph Swan and Thomas Edison to invent the incandescent light bulb. It consisted of a container of mercury (A) allowed by a valve (C) to fall one drop at a time into a long glass tube (XD) which empties into a reservoir (H). Air is trapped between the drops in the tube and carried by the weight of the mercury out the bottom of the tube. This slowly evacuates the container (R) attached at the top.", by Augustin Privat Deschanel, 1881, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Spring scale: "Manual spring scale from the manufacturer Salter's. The scale can be suspended from the top of the scale using a hook. The item to be weighed is suspended from a flat rod with a hook at the bottom of the scale, which is pulled out of the scale by the weight of the item to be weighed. Unfortunately, the hook is missing. The weights in the first illustration are not part of the scale and simulate the item to be weighed. The scale displays the weight in imperial measurements. The internal rod moves a pointer approximately in the centre of the scale which shows the weight on a round scale. The large numbers are in British pounds (abbreviated to lbs). The 16 subdivisions in between correspond to ounces. (1 pound = 16 ounces). The scale can weigh a maximum of 30 pounds. This means that the pointer can circle the dial 3 times. There are markings for 10 and 20 pounds on the pull-out rod, which are then to be added to the pointer display (see last illustration). Marked texts on the scale from top to bottom: CLASS II SALTER'S IMPROVED CIRCULAR SPRING BALANCE TO WEIGH 30 lbs BY OUNCES (here is the dial with the pointer) EACH 10 lb IS MARKED ON THE SLIDE THE INTERMEDIATE WEIGHTS ON THE CIRCLE SALTER Below the company logo a Straffordshire knot with an arrow through it and an S in it On the left edge above the dial is a lead calibration mark. Inside this is a crown, with the letters E and R to the left and right below it and the number 379 below this. E R and the crown could mean Edward VII Rex (* 9 November 1841; † 6 May 1910, King from 1901). At the top left above these stamps is a hallmark that looks as if it was used to invalidate the calibration. Various numbers are stamped above and next to the calibration mark, namely: /03 /02 14 /01 /99 17 8", by HelgeRieder, 2024, licensed under CC0, via Wikimedia Commons. View source. View in tree.
• Spring scissors: "Scissors", licensed under CC0, via Wikimedia Commons. View source. View in tree.
• Spritsail: "Roman ship with spritsail on the Copenhagen Sarcophagus from the late 3rd century AD. It is one of the oldest depictions of spritsails in the history of navigation. Find spot: allegedly Ostia. Current location: Ny-Carlsberg Glyptothek in Copenhagen (Denmark), Inv.-No. 1299. The pic above shows a copy displayed at the Museum für Antike Schiffahrt (Museum for Ancient Navigation) in Mainz, Germany.", by Gun Powder Ma, 2008, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Stainless steel: "Collectie / Archief : Fotocollectie Van de Poll Reportage / Serie : Reclame voor Wade & Butcher Beschrijving : Fruitschaal van roestvrij staal Datum : 1936 Trefwoorden : fruitschalen, huishoudelijke artikelen, metalen, reclame, staal Instellingsnaam : Pomona Fotograaf : Poll, Willem van de, [onbekend] Auteursrechthebbende : Nationaal Archief Materiaalsoort : Glasnegatief Nummer archiefinventaris : bekijk toegang 2.24.14.02 Bestanddeelnummer : 189-1136", by Willem van de Poll, 1936, licensed under CC0, via Wikimedia Commons. View source. View in tree.
• Stamp seal: "Stamp seal and modern impression. Horned animal and bird,6th–5th millennium B.C. Northern Syria or Southeastern Anatolia. Ubaid Period. Metropolitan Museum of Art", by Metropolitan Museum of Art, 2019, licensed under CC0, via Wikimedia Commons. View source. View in tree.
• Standard diving dress: "Emil Racovitza as diver at Observatoire océanologique de Banyuls-sur-Mer. The upside down sign the man is holding says "Photographie sous-marine" (underwater photography).", by Louis Boutan, 1899, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Standard Model of particle physics : "Standard model of elementary particles: the 12 fundamental fermions and 5 fundamental bosons. Brown loops indicate which bosons (red) couple to which fermions (purple and green). Please note that the masses of certain particles are subject to periodic reevaluation by the scientific community. The values currently reflected in this graphic are as of 2024 and may have been adjusted since. For the latest consensus, please visit the Particle Data Group website linked below.", by Cush, 2019, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Star chart: "Nebra Sky Disk", by Frank Vincentz, 2022, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Static random-access memory: "Integrated circuit die image of a STM32F103VGT6 ARM Cortex-M3 MCU (microcontroller) with 1 Mbyte Flash, 72 MHz CPU, motor control, USB and CAN. Die size of 5339x5188 µm. View is from a Scanning Electron Microscope looking at the 180 nanometre SRAM cells on the die.", by ZeptoBars, 2013, licensed under CC BY 3.0, via Wikimedia Commons. View source. View in tree.
• Statistical language model: "diagram for 1-skip-2-gram Matplotlib code import numpy as np import matplotlib.pyplot as plt # Example sentence words = ["the", "rain", "in", "Spain", "falls", "mainly", "on", "the", "plain"] positions = np.arange(len(words)) fig, ax = plt.subplots(figsize=(10, 3)) ax.set_ylim(-1.2, 1.2) ax.set_xlim(-0.5, len(words) - 0.5) ax.axis('off') # Plot words for x, w in zip(positions, words): ax.text(x, 0, w, ha='center', va='center') # Parameters for curve offset and amplitude offset_top = 0.4 offset_bottom = -0.4 amplitude = 0.6 # Draw curves for bigrams (2-grams) on top for i in range(len(words) - 1): j = i + 1 t = np.linspace(0, 1, 100) xs = positions[i] + t * (positions[j] - positions[i]) ys = offset_top + amplitude * np.sin(np.pi * t) ax.plot(xs, ys, color='black') # Draw curves for 1-skip-2-grams on bottom for i in range(len(words) - 2): j = i + 2 t = np.linspace(0, 1, 100) xs = positions[i] + t * (positions[j] - positions[i]) ys = offset_bottom - amplitude * np.sin(np.pi * t) ax.plot(xs, ys, color='black') plt.tight_layout() # plt.show() plt.savefig('skip-gram.svg')", by Cosmia Nebula, 2025, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Steam hammer: "Steam engine technology", by F.A. Brockhaus, Berlin und Wien, 1894, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Steam injector: "Steam water injector invented by Henri Giffard.", by Robert Routledge, 1890, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Steam locomotive: "Engraving from Science Museum", by Science Museum, 1958, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Steam shovel: "Excavator of W. S. Otis.", by Unknown authorUnknown author, 1841, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Steam turbine: "Parson's Compound Steam Turbine - 1887 - Project Gutenberg eText 17167.png", licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Steam velocipede: "PERREAUX, 1ère moto de l'Histoire; auteur : Guy Rolland", by Guy Rolland, 2015, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Steam-powered aircraft: "French_patent_205155_of_19_April_1890 for Clement Ader Avion", by PHGCOM, 1890, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Steam-powered battleship: "The Napoleon At Toulon In 1852", by Barthélemy Lauvergne, 1860, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Steam-powered water pump: "Savery Steam Engine, 1698", by Original: Unknown Source: Institute of Human Thermodynamics and IoHT Publishing Ltd., 1698, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Steamboat: "D'AbbansSteamshipModel.jpg", by World Imaging, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Steamboat transport: "Replica of the Clermont (aka North River Steamboat) in 1909.", by Detroit Publishing Co., 1909, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Steel plough: "Early John Deere plow, circa 1845, made in Grand Detour, Illinois. Displayed at The Henry Ford Museum, Dearborn, Michigan", by Rmhermen, 2017, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Steel-framed building: "The 1889 RandMcNally building (shown as #4) in Chicago on Adams St. between Wells and Quincy. Demolished 1911. From Rand McNally "bird's eye views" from 1890s guides.", by Rand McNally (1893), 2011, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Steelmaking with partial decarbonization: "National Museum: China through the Ages, Exhibit 8. Complete indexed photo collection at WorldHistoryPics.com.", by Gary Todd, 2011, licensed under CC0, via Wikimedia Commons. View source. View in tree.
• Steelpan: "Bilder vom Zelt Musik Festival 2017 in Freiburg im Breisgau Nach der Klassikmatinee", by joergens.mi, 2017, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Steering oar: "Tomb of Menna - funeral boat 200dpi.jpg", by Unknown artistUnknown artist, 1422, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Stem cell: "Transmission electron micrograph of a mesenchymal stem cell displaying typical ultrastructural characteristics.", by Robert M. Hunt, 1997, licensed under CC BY 3.0, via Wikimedia Commons. View source. View in tree.
• Stepped reckoner: "The Staffelwalze, or Stepped Reckoner, a digital calculating machine invented by Gottfried Wilhelm Leibniz around 1672 and built around 1700, on display in the Technische Sammlungen museum in Dresden, Germany. It was the first known calculator that could perform all four arithmetic operations; addition, subtraction, multiplication and division. 67 cm (26 inches) long. The cover plate of the rear section is off to show the wheels of the 16 digit accumulator. Only two machines were made. The single surviving prototype is in the National Library of Lower Saxony (Niedersächsische Landesbibliothek) in Hannover; this is a contemporary replica.", by User:Kolossos, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Stepper: "Autostep i-line stepper for microelectronic photolithography", by a13ean, 2012, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Stereo slide viewer: "View-Master Model E", by ThePassenger, 0200, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Stereolithography: "Schematic representation of stereolithography; a light-emitting device a) (laser or dlp) selectively illuminate the bottom of a tank b) filled with a liquid photo-polymerizing resin; the solidified resin d) is progressively dragged up by a lifting platform e).", by Paolo Cignoni, 2017, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Stereophonic sound: "Cutting head of lathe for phonograph disks by Neumann, Berlin. Developed for TELDEC's Direct Metal Mastering process for vinyl records.", by 32bitmaschine, 2008, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Stereoscope: "Visore stereoscopico portatile di tipo Brewster, J. Fleury - Hermagis, 1870, con messa a fuoco manuale. Per la visione di lastre e stampe stereoscopiche 8,5x17cm. Museo nazionale della scienza e della tecnologia Leonardo da Vinci, Milano.", by Alessandro Nassiri, 2014, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Sternpost-mounted rudder: "I took this photo at the National Museum in Beijing. From the Eastern Han dynasty 25-220 CE. Guangzhou. Said to be the earliest known representation of a rudder. This craft could be used both on rivers and at sea. Note the roofed compartments with doors and windows and sailors", by John Hill, 2011, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Stethoscope: "Made of wood and brass, this is one of the original stethoscopes belonging to the French physician Rene Theophile Laennec (1781-1826) who devised the first stethoscope in 1816. It consists of a single hollow tube. The familiar binaural stethoscope, with rubber tubing going to both ears, was not developed until the 1850s. Regarded as the father of chest medicine, Laennec demonstrated the importance of the instrument in diagnosing diseases of the lungs, heart and vascular systems. Ironically, he died of tuberculosis.", by Science Museum London / Science and Society Picture Library, 2013, licensed under CC BY-SA 2.0, via Wikimedia Commons. View source. View in tree.
• Stirling engine: "Eigenbau Stirling Motor 1996 spezifische Quelle: privat Foto: Pedro Servera († 2005) Erstellt: Datum 2005 Bild-GFDL", by The original uploader was Pedro Servera at German Wikipedia., 2005, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Stirrup: "Gilded wooden stirrup.", by Augusthaiho, 2018, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Stocking frame: "Stocking Frame - a mechanical knitting machine", by John Beniston, 2005, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Stone tool: Copyright: MPK-WTAP. View in tree.
• Stonemasonry: "Photo of Gobekli Tepe", by Immanuelle, 2018, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Stored-program computer: "Manchester University SSEM 'Baby' replica on display at the Museum of Science and Industry in Manchester.", by Users Ian Dunster, Racklever on en.wikipedia, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Straight razor: "Egypt, New Kingdom (1569 - 1081 BCE) or later Tools and Equipment; blades Bronze Length: 6 7/8 in. (17.5 cm); Width: 4 3/8 in. (11.1 cm) Gift of Frank J. and Victoria K. Fertitta (M.80.198.24) Egyptian Art", licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Stratonautical space suit: "Space suit designed by military engineer Emilio Herrera for stratospheric balloon", by Nationaal Archief, 2012, licensed under No restrictions, via Wikimedia Commons. View source. View in tree.
• Street sweeper: "Whitworth's Straßenreinigungsmaschine.", by Johann Jacob Weber (Hrsg.), 1803–1880, 1843, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Strong focusing: "Sextupole magnets used for focussing the electron beam in the storage ring, as used at the Australian Synchrotron, Clayton, Victoria.", by jjron, 2007, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Strontium: "The chemical element strontium as synthetic crystals, sealed under argon in a glass ampoule, purity (99.95 %). Size of the image ca. 3cm * 4,7cm", by Alchemist-hp (talk) (www.pse-mendelejew.de), 2011, licensed under FAL, via Wikimedia Commons. View source. View in tree.
• Structure of DNA: "Pencil sketch of the DNA double helix by Francis Crick. It shows a right-handed helix and the nucleotides of the two anti-parallel strands. Archives & Manuscripts Keywords: DNA; Molecular Biology; Nucleic Acids; Nobel Prizes; DNA50; Francis Harry Compton Crick; Genetics; Nucleic acid; Base Pairing", licensed under CC BY 4.0, via Wikimedia Commons. View source. View in tree.
• Submarine: "Reconstitution en coupe du Nautilus (1799) de Robert Fulton, à la Cité de la Mer (Cherbourg, Normandie)", by Ji-Elle, 2008, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Submarine communication cable: "New-York. Eine Kabel-Legung, Italien-Amerika. In Rockoway Beach wurde das Ende eines neuen Unterseekabels an Land gezogen, welches New-York mit Süd-Europa verbinden soll. Es ist das erste direkte Kabel zwischen den Vereinigten Staaten und Süd-Europa. Es läuft von New-York zu den Azoren und von dort über Malaga in Spanien nach Rom. Das Bild zeigt das Anlandziehen des Kabels in der Nähe New-Yorks. Die Gesamtlänge dieser neuen Verbindung beträgt 4704 Seemeilen.", by Unknown authorUnknown author, 1925, licensed under CC BY-SA 3.0 de, via Wikimedia Commons. View source. View in tree.
• Subtractive color film: "Kodachrome slide with a paper frame", by Harke, 2009, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Suction pump: "first piston", by Taccola, 1450, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Sugar beet: "Beta vulgaris L.", by Amédée Masclef, 2001, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Sulfite wood pulp process: "Photo of the Bergvik paper pulp factory in 1872", by Unknown authorUnknown author, 1872, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Sulfur: "Sulfur crystals on the matrix (4.8 × 3.5 × 3 cm). Found from El Desierto mine, San Pablo de Napa, Daniel Campos Province, Potosí, Bolivia", by Ivar Leidus, 2021, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Sulfur lamp: "Sulfur lamp.", by Ejkum at Polish Wikipedia, 2007, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Sulfur matches: "Lighting a match.", by Sebastian Ritter (Rise0011), 2006, licensed under CC BY-SA 2.5, via Wikimedia Commons. View source. View in tree.
• Sulfuric acid: "96% sulfuric acid", by W. Oelen, 2011, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Sundial: "World's oldest Sundial, from Egypt's Valley of the Kings (c. 1500 BC) ; is it a sundial ???", by University of Basel, 2014, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Sunglasses: "Lavoisier conducting an experiment related combustion generated by amplified sun light. Source http://historyofscience.free.fr/Comite-Lavoisier/f_galerie_sur_lavoisier.htm", licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Sunscreen: "Sunscreen SPF 30 applied to my back and photographed using normal and UV photography at the Cheltenham Science festival. Camera: converted Nikon D40 with 50mm enlarger lens. Exposure 1/500s for normal light, 1/5s for UV.", by Photograph by Andrew Steele (http://andrewsteele.co.uk), jointly released into the public domain by the person in the photo (wiki user HYangWong)., 2013, licensed under CC0, via Wikimedia Commons. View source. View in tree.
• Super heavy-lift launch vehicle: "This is a picture of All Saturn V Launches - created by en:User:Reubenbarton using Paint Shop Pro. The individual launch images came from the NASA Image eXchange (NIX) web site: http://nix.nasa.gov/ downloaded from en.wikipedia, original uploader was en:User:Reubenbarton", by Maldoror, 2005, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Supercomputer: "UNIVAC LARC-BRL61-0959.jpg", licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Superconducting magnet: "Schematic of a 20T superconducting magnet from Los Alamos National Laboratory.", by US Department of Energy, 2009, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Superconductors: "A high-temperature (liquid nitrogen cooled) superconductor levitating above a permanent magnet (TU Dresden)", by Henry Mühlpfordt, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Superheterodyne radio receiver: "One of the first prototype superheterodyne radio receivers built by inventor Edwin Armstrong. The superheterodyne, the circuit used in virtually all modern radios, was invented by Armstrong in 1918 while he worked in a US Army Signal Corps laboratory in Paris during World War 1. This is one of the receivers constructed at that laboratory, shown in a 1920 article in an amateur radio magazine. It is constructed in two parts. The lefthand section consists of the mixer and local oscillator. The oscillator uses an Armstrong "tickler" circuit. The two large knobs are the input tuning capacitor (left, labeled TUNING) and the local oscillator tuning capacitor (right, labeled HETERODYNE). The upper center multiposition switch controls the filament current, while the lower center knob controls the feedback coupling of the oscillator. The righthand section contains an IF transformer filter, 3 stages of RC-coupled IF amplification and a detector stage. The multiposition switch on this section controls the filament current of the 4 tubes, while the righthand knob (labeled AMPLIFICATION) controls the gain of the amplifier. All the tubes are VT triodes made by Western Electric. The circuit uses an IF of around 75 kHz. Caption: "One of the first complete Armstrong amplifiers built in Armstrong's Paris laboratory. The cabinet at the left contains the tuning and heterodyne circuit and at the right the amplifying cabinet is shown"", by H. W. Houck, 1920, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Superphosphate: "(nl:Tripelsuperfosfaat) triple phosphate;", by Rasbak, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Supersonic airliner: "“Tu-144 passenger airliner”. A Tupolev Tu-144 supersonic passenger airliner.", by Lev Polikashin / Лев Поликашин, 1969, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Supersonic flight: "The #46-062 Bell X-1 rocket-powered experimental aircraft (known for becoming the first piloted aircraft to fly faster than Mach 1, or the speed of sound, on October 14, 1947) photographed during a test flight.", by NASA, 1947, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Surface-to-air missile: "Nike family, From left, MIM-3 Nike-Ajax, MIM-14 Nike-Hercules.", by U.S. Army, 1961, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Surgery under anesthesia: "This is a picture from Hanaoka Seishu's work, "Surgical Casebook". It is a part of the National Library of Medicine's "Turning the Pages" project, which digitizes older medical texts that should no longer be handled in physical form", by Hanaoka Seishu, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Swiss army knife: "First Swiss Army knife from 1891, produced by Wester & Co Solingen / Germany.", by Cutrofiano, 2009, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Sword: "Apa Schwerter.jpg", licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Synchrotron: "An early 300 MeV electron synchrotron at University of Michigan, 1949. Built by H. Richard (Dick) Crane, this was the first synchrotron to use the "racetrack" design; it had 4 straight sections alternating with 4 quadrant electromagnets. It had a large 500 keV Cockcroft-Walton generator (visible at left rear) as injection accelerator, the vertical injection beam tube is visible at right in front of figure. The 1 meter diameter of the quadrant magnet bends gave it a theoretical maximum energy of 300 MeV and it was briefly operated at that energy, although for most of its life it operated at a lower energy of 40 MeV. Information from Innovation Was Not Enough: A History of the Midwestern Universities Research Association (Mura), World Scientific Co., 2009, ISBN 981283284X.", by Albert J. Forman, 1949, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Synchrotron with superconducting magnets: "Fermi National Accelerator Laboratory, Main Ring and Main Injector as seen from the air. The pill-shaped ponds dissipate waste heat from the equipment.", by Fermilab, Reidar Hahn, 2003, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Synthetic diamond: "The first synthetic diamonds from the ASEA QUINTUS press in Stockholm 1953. The size of each crystal was about 0,1 mm.", by Erik Lundblad, 1953, licensed under CC BY 4.0, via Wikimedia Commons. View source. View in tree.
• Synthetic dye: "Blick in die Historische Farbstoffsammlung der TU Dresden (de:Historische Farbstoffsammlung der TU Dresden)", by JWBE, 2012, licensed under CC0, via Wikimedia Commons. View source. View in tree.
• Synthetic insulin: "Ampule inzulínu Actrapid (pro užití inzulínkou) a Novorapid (pro užití do IP) od firmy NovoNordisk", by Mr Hyde at Czech Wikipedia (Original text: moje foto), 2007, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Synthetic rubber: "This sheet of synthetic rubber coming off the rolling mill at the plant is now ready for drying, B.F. Goodrich Co., Akron, Ohio. Synthetic rubber made by the "ameripol" process is derived from butadiene (a petroleum derivative). In this rolling mill the crumbs of rubber are squeezed dry of excess water and pressed together into the blanket shown here In 1940, B.F. Goodrich Company scientist Waldo Semon developed a cheaper version of synthetic rubber known as Ameripol. It made synthetic rubber production much more cost effective.", by Alfred T. Palmer, 1941, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Synthetic ultramarine: "Ultramarinepigment.jpg", licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Syphon recorder: "Automatic Syphon Telegraph Receiver Muirhead's Syphon recorder", by Andy Dingley (scanner), 1903, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Syringe: "2ml Rekordspritze aus Metall/Glas (zerlegbar)", by Julo, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• System of measurement: "Gudea, prince de Lagash. Statue en diorite dite ""l'architecte à la règle", dédiée à la déesse Gatumdu, v. 2120 av. J.-C (période néo-sumérienne). Musée du Louvre (Paris). Trouvée dans les ruines de Girsu à Tellō (Iraq).", by Michel wal, 2009, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Tablet computer: "GRiD 2260 in tablet mode", by ressedue, 2014, licensed under CC BY 2.0, via Wikimedia Commons. View source. View in tree.
• Tabulating machine: "Il sistema è costituito da un mobile in legno che presenta in alto un vano con vetrina contenente un totalizzatore a contatori, e, alla sua metà, un ripiano su cui è posto un dispositivo in metallo atto alla lettura delle schede perforate. Questo dispositivo è composto da una griglia di aghi posizionata superiormente e capace di traslare verticalmente con moto a compasso articolato. Ciascun ago della griglia è collegato ad un circuito elettrico che fa capo ai contatori in alto e ad un corrispondente "bicchiere" metallico contenete mercurio (ora non presente) posto a mo' di contatto alla base del dispositivo Un altro mobile in legno posto lateralmente al primo e elettricamente connesso al dispositivo ad aghi del primo mobile in legno, svolge la funzione di selezionatrice (sorter). Le caselle sono 11 e ciscuna è minita di sportello a coperchio in ottone. Funzione serviva a leggere, contare e selezionare le schede perforate a 20 colonne. Modalità d'uso Azionando la pressa ad aghi fissata alla parte del complesso con i contatori, veniva letta una scheda alla volta; la lettura da parte degli aghi, chiudeva o non dei circuiti elettrici che azionavano i contatori posti sul pannello superiore e contemporaneamente si apriva la casella corrispendente sul sorter posto lateralmente ed elettricamente connesso al lettore ad aghi. L'operatore, quindi, inseriva manualmente la scheda appena letta nella casella aperta che poi si richiudeva automaticamente. Infine, l'operatore dovava riportare i risultati parziali o finali dei contatori e fare poi le eventuali somme. Notizie storico-critiche Si tratta di un modello ricostruito sulla base dell'originale primo complesso meccanografico elettrocontabile a schede perforate a 20 colonne, realizzato da H. Hollerith Il sistema originale era costituito da: - una perforatrice a pantografo (separata, vedi scheda con NCTN 02039760); - una pressa ad aghi per la lettura di una scheda alla volta (fissata alla parte del complesso con i contatori), dove la scheda non viene letta per intero bensì solo nelle 40 posizioni connesse a uno dei contatori; - un pannello di contatori a quadrante dove ciascun contatore ha una lancetta per le unità e una per le centinaia (i conteggi parziali o finali devono essere trascritti a mano a cura dell’operatore); - una selezionatrice (ordinatrice o sorter, connessa elettricamente alla parte con i contatori) per la raccolta di gruppi di schede con dati omogenei; ogni casella ha un coperchio la cui apertura è comandata dai circuiti di lettura opportunamente connessi e la scheda letta viene "imbucata" manualmente nella casella attivata, dodichè il coperchio ritorna. in posizione di riposo Alle origini delle macchine per l'elaborazione di informazioni vi è la necessità di riuscire ad aumentare la velocità di leggere dati, classificarli e, se necessario, elaborarli Il pioniere di questa disciplina fu appunto Herman Hollerith ( U.S.A. 1860 - 1929), un esperto di statistica, che, partendo dalle idee di Jacquard, progettò nel 1884 una macchina (Hollerith Electric Tabulating System) che era in sostanza una addizionatrice automatica in grado di leggere schede sulle quali erano perforati dei dati, totalizzando i dati letti. La prima applicazione fu nel censimento USA del 1890 dove il sistema fu usato per raccogliere dati, quali nome, età, sesso ed indirizzo di una persona sotto forma di fori praticati su una scheda di cartoncino e per poi contarli elettricamente. La lettura elettrica era realizzata mediante aghi che, penetrando nei fori delle schede, chiudevano dei circuiti elettrici utilizzati per attivare dei contatori.", by I.B.M. Italia (committente), Hollerith H. Herman (inventore), licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Talking drum: "TalkingDrum.jpg", licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Tally stick: "Bone tool and possible mathematical device that dates to the Upper Paleolithic era discovered in Ishango", by Joeykentin, 2022, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Tanja sail: "Relief panel of a ship at Borobudur", by MichaelJLowe, 2005, licensed under CC BY-SA 2.5, via Wikimedia Commons. View source. View in tree.
• Tank: "Mark I series tank and crewman at Thetford in "Solomon" camouflage", by Bain News Service, 1916, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Tanned leather: "Permennter-1568.png", licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Tape recorder: "German Wehrmacht tape recorder AEG Magnetophon Tonschreiber B with AEG 2-hole bobbies, built after 1942, from a German radio station in World War II. Military History Museum of Artillery, Engineers and Signal Corps, Saint Petersburg", by George Shuklin (talk), 2007, licensed under CC BY-SA 1.0, via Wikimedia Commons. View source. View in tree.
• Tattoo machine: Patent drawing from Google Patents. View source. View in tree.
• Taximeter: "Title: Frau Papp driving taximeter auto, Berlin Abstract/medium: 1 negative : glass ; 5 x 7 in. or smaller.", by Bain News Service, publisher, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Technetium: "Technetium sample inside a sealed glass ampoule, filled with argon gas. 6x1 mm goldfoil covered with 99Tc powder (electroplated).", by Marco Cardin, 2020, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Technetium-99m radioactive tracing: "The first technetium-99m generator developed at Brookhaven National Laboratory, circa 1958, shown without shielding. Technetium-99m is the most commonly used medical radioisotope.", by Brookhaven National Laboratory., 1958, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Teeth-cleaning twig: "Bunches of teeth cleaning twigs displayed near Kalka,India", by Harvinder Chandigarh, 2016, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Telautograph: "A perspective view of the first commercial model of Elisha Gray's Telautograph transmitter and receiver, identical in appearance to those exhibited at the Chicago Worlds Fair in 1893. The left-hand transmitter unit would encode the position of a writing pencil as a series of pulsed currents of different levels and polarities, to be transmitted to and reproduced by the receiver on the left, where a capillary tube ink pen is moved across the paper by electromagnetic clutches and escapements. Shared by the American National History Museum and retrieved from the Smithsonian Image Delivery Service in 2023 under CC0 license. Pub date actually unknown.", by National Museum of American History; Smithsonian Institution, 2023, licensed under CC0, via Wikimedia Commons. View source. View in tree.
• Telegraph sounder: "120 Ohm mainline sounder manufactured by J H Bunnell & Company", by Smoketronics, 2011, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Telephone: "An actor portraying Alexander Graham Bell speaking into a early model of the telephone for a 1926 promotional film by the American Telephone & Telegraph Company (AT&T): see 1926 recreation of Alexander Graham Bell inventing the telephone. AT&T Archives. Archived from the original on 2011-06-22. Retrieved on 22 June 2011.", by Unknown authorUnknown author; film commissioned by AT&T., 1926, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Telephone exchange: "A Telephone Exchange operator in en:Richardson, Texas, circa 1900. This was scanned by the uploader from the Richardson Public Library local history archives, courtesy of the Richardson Historical and Genealogical Society.", 1900, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Telescope: "Early depiction of a ‘Dutch telescope’ from the “Emblemata of zinne-werck” (Middelburg, 1624) of the poet and statesman Johan de Brune (1588-1658). The print was engraved by Adriaen van de Venne, who, together with his brother Jan Pieters van de Venne, printed books not far from the original optical workshop of Hans Lippershey.", by Adriaen van de Venne, 1624, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Television set: "RCA Model 630-TS television set seen in a museum. Its caption indicates it was the first mass produced TV set and was sold in 1946 and 1947.", by Fletcher6, 2012, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Tellurium: "Metallic tellurium, diameter 3.5 cm", by Unknown authorUnknown author, licensed under CC BY 3.0, via Wikimedia Commons. View source. View in tree.
• Terrestrial television: "One of the first television broadcasting antennas in the United States, installed on the top of the Empire State Building, New York, in 1939, belonging to NBC's experimental television station W2XBS. W2XBS had been broadcasting low-resolution experimental TV transmissions since 1931, but in 1937 went to RCA's new television standard of 441 lines interlaced with a frame rate of 30 Hz, and in 1938 began the first publicly scheduled broadcasts, 5 hours daily, in preparation for the rollout of commercial television at the New York World's Fair in 1939. The new antenna, built by NBC's parent company RCA, had two separate elements to broadcast the separate audio and video signals. The top element is a pair of linked dipoles which radiated the 49.75 MHz audio signal. The bottom is a variety of turnstile antenna that radiated the 46.5 MHz video signal. It consists of two perpendicular dipole elements driven 90° out of phase for omnidirectional coverage. This was a new design at the time, devised to give the antenna a wide bandwidth of 30 MHz. The range of reception was about 50 miles. The antennas incorporated heating elements for deicing. The rod at the top is a lightning rod. Information from "First public schedule gives television impetus", Radio World, May 1938, p. 57", by Unknown authorUnknown author, 1939, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Tesla coil: "Lightning Simulator - Questacon, Canberra", by fir0002 flagstaffotos [at] gmail.com Canon 20D + Tamron 28-75mm f/2.8, licensed under GFDL 1.2, via Wikimedia Commons. View source. View in tree.
• Text-to-image model: "Sample of 8 images generated by alignDRAW, one of the first text-to-image models, using the prompt "A stop sign is flying in blue skies."", by Algorithmically generated by the alignDRAW AI model, 2015, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Théâtre optique: "First public performance of Reynaud's 'Theatre Optique' in Paris 1892.", by Louis Poyet, 1892, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Théâtrophone: "Le Théâtrophone. A poster depicting the théâtrophone", by Jules Chéret, 1896, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Theodolite: "Exhibit in the Putnam Gallery - Harvard University - Cambridge, Massachusetts, USA.", by Daderot, 2020, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Theremin: "Photograph of Alexandra Stepanoff playing the theremin on NBC Radio Original caption on source:Recognize this instrument ? Well, hardly, for it's the new Theremin Ether-wave Music box. And of course you have not failed to note the lovely young lady -- she is MME ALEXANDRA STEPANOFF, musician of marked ability, all of which is required to coax exquisite melody from this remarkable instrument. More information Albert Glinsky (2000) Theremin: Ether Music and Espionage, University of Illinois Press, p. 86 ISBN: 978-0-252-02582-2. "​In July, writers for two New York Communist organs, A. B. Magil, of the Daily Worker, and William Abrams, of the Daily Freiheit, dropped in on the inventor for a feature story. “Prof. Leon Theremin led the way into the modestly furnished bedroom of his suite at the Plaza Hotel,” Magil wrote. “... a pupil of his was practing on the new ether-music instrument.” The pupil was Alexandra Stepanoff, Theremin's first student on U.S. soil -- a young, recent immigrant to America. Slender and graceful, with delicate features, dark, smartly cropped hair, and an assured smile, she remainiscent of the very young Galbo. In Russia she had been a concert singer and now, under the professor's spell, she fluently transferred her vocal technique to the ether instrument. Alexandra had come to the inventor's attention through the network of New York's Russian community with which he had surrounded himself, and along with Goldberg she became one of the first discilples of the instrument. "", by What's On the Air Company, 1930, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Thermionic diode: "The first prototype Fleming valves. The Fleming valve, invented in 1904 by John Ambrose Fleming, as a detector for radio waves in early radio receivers, was the first thermionic diode and the first vacuum tube. The basic configuration consisted of an evacuated glass bulb containing two electrodes: a cathode in the form of a wire filament heated white-hot by a current through it, and a metal anode usually consisting of a flat plate. Since only the filament produces electrons, the current of electrons through the tube can only pass in one direction, from filament to anode. In these early tubes, the filament is the vertical loop of wire, while the anode has various shapes, such as the coil of wire in the lefthand tube. The caption says: "Photograph of the oscillation valves first employed by Dr. J. A. Fleming, FRS, in October 1904, for the rectification of high-frequency electric oscillations as used in wireless telegraphy"", by John Ambrose Fleming, 1904, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Thermionic emission: "A replica of one of the bulbs with which Thomas Alva Edison discovered the Edison Effect (thermionic emission) in the early 1880s. Made by Clayton H. Sharp in 1921 as an experiment to see if Edison's bulb could be used like a Fleming valve as a detector in a radio receiver to rectify radio waves. It worked. It consists of an Edison incandescent light bulb, an evacuated glass bulb with a hairpin shaped bamboo carbon filament, with an additional platinum plate (visible between the arms of the filament) attached to wires emerging from the base of the bulb. A current through the filament heated it white-hot. Edison discovered that the hot filament emitted negatively-charged particles (later discovered to be electrons) an effect that was called the Edison effect. He demonstrated this by applying a separate voltage between the filament and plate. When the plate had a positive voltage, the electrons were attracted to it and a current flowed through the tube from filament to plate. When the plate had a negative voltage, the electrons were repelled so no current flowed through the tube. Edison found no practical use for this effect, but in 1904 John Ambrose Fleming invented a similar tube called the Fleming valve which was used to rectify radio signals in the first radio receivers, which evolved into the diode vacuum tube. Alterations to image: partially removed aliasing artifacts (crosshatched lines in background) due to scanning of halftone photo using FFT filter in GIMP.", by Clayton H. Sharp, 1921, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Thermoscope: "instrument Musée des Arts et Métiers", by Chatsam, 2014, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Thermostat: "Cornelius Drebbel (1572-1633), Alcmariensis. Son of Jacob Jansz Dremmel en Hilgont Jans.", by Christoffel van Sichem I‎I‎, 1631, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Thin-film solar cell: "Final installation and layout of Uni-Solar Ovonic’s thin Film Flexible Solar PV panels", by Fieldsken Ken Fields, 2008, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Thin-film transistor: "Color TFT-LCD Layout.png", licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Thorium: "Thorium sample (99.9 % = 3N), thin sheet under argon in a glass ampoule, ca. 0.1 g", by Alchemist-hp (talk) (www.pse-mendelejew.de), 2006, licensed under FAL, via Wikimedia Commons. View source. View in tree.
• Three-field crop rotation: "Three Field System used in medieval agriculture", by MScharwies, 2017, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Three-point hitch: "Polish Ursus C-360-3P tractor. Perkins engine.", by Pibwl, 2008, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Three-strip color film: ""Technicolor is natural color" Paul Whiteman stars in the King of Jazz - from, The Film Daily, Jul-Dec 1930 (page 218 crop).jpg", by New York, Wid's Films and Film Folks, Inc., licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Threshing board: "Cylinder-seal impression that comes from Arslantepe-Malatya (Turkey). It dates from 4th millennium B.C. It shows a ceremonial threshing with threshing-sledge", by José-Manuel Benito, 2006, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Threshing machine: "Drawing of a horse-powered thresher from a French dictionary (published in 1881)", by Unknown authorUnknown author (Dictionnaire d'arts industriels), 1881, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Throwing stick: "Aboriginal craft - National Botanical Gardens", by fir0002 flagstaffotos [at] gmail.com Canon 20D + Tamron 28-75mm f/2.8, licensed under GFDL 1.2, via Wikimedia Commons. View source. View in tree.
• Thyratron: "Thyratronsmall.jpg", licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Thyristor: "SCR1369.jpg", licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Ticker tape: "Thomas Edison Gold & Stock Telegraph, Henry Ford Museum, Dearborn, MI", by H. Zimmer, 2004, licensed under CC BY 3.0, via Wikimedia Commons. View source. View in tree.
• Time clock: "Time clock in the Museum at Wookey Hole Caves", by Rodw, 2008, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Time-sharing: "Computer user around 1978 at the University of Wisconsin, Madison, working at a Unix terminal.", by Dave Winer, 2009, licensed under CC BY-SA 2.0, via Wikimedia Commons. View source. View in tree.
• Tin bronze: "Sumerian; Lyre ornament; Metalwork-Ornaments", 2600, licensed under CC0, via Wikimedia Commons. View source. View in tree.
• Tin can: "Arabia Steamboat Museum, 400 Grand Boulevard, Kansas City, Missouri, USA. The ship Arabia sank in the Missouri River on September 5, 1856, and was rediscovered in 1988. Photography was permitted in the museum without restriction.", by Daderot, 2011, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Tin extraction: "Sword, bronze, Bronze Age, around 800 B.C.E. JC???, Museum of National Antiquities, Saint-Germain-en-Laye", by User:Calame, 2006, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Tin-mercury amalgam mirror: "Venezia, specchio da tavolo, 1590 ca.", by sailko, 2011, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Titanium: "A titanium crystal bar, high purity 99,995 %, made by the iodide process at URALREDMET in the Soviet era. Weight ≈283 g, ≈5.5 " long, ≈1 " diameter", by Alchemist-hp (pse-mendelejew.de), 2009, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• TNT: "Trinitrotoluene", by Daniel Grohmann, 2013, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Tobacco: "Dunhill Early Morning Pipe Tobacco, 1990's Murray", by Sjschen (Sjschen), 2007, licensed under CC BY 2.5, via Wikimedia Commons. View source. View in tree.
• Toe stirrup: "Stirrup on an (admittedly dirty) endurance saddle", by BLW, 2007, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Toilet paper: "Toilet paper", by Brandon Blinkenberg, 2004, licensed under CC BY 2.5, via Wikimedia Commons. View source. View in tree.
• Tokamak: "A worker inside the DIII-D vacuum vessel during a maintenance period in 2017", by Rswilcox, 2017, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Tool steel and air-hardening steel: "Identifier: toolsteelsdatata00carn (find matches) Title: Tool steels, data and tables appertaining to electric tool steels Year: 1918 (1910s) Authors: Carnegie steel company. (from old catalog) Subjects: Tool-steel Publisher: Pittsburgh, Pa., Carnegie steel company Contributing Library: The Library of Congress Digitizing Sponsor: Sloan Foundation View Book Page: Book Viewer About This Book: Catalog Entry View All Images: All Images From Book Click here to view book online to see this illustration in context in a browseable online version of this book. Text Appearing Before Image: 1. Normal Steel as Rolled Fig. 3.—Metcalf Test PiecesCarnegie Electric Tool Steel No. 1 *,fe.W HEAT TREATMENT TESTS 4. Overheated Text Appearing After Image: Fig. 4. Full Size Test Piece FracturesCarnegrie Electric Tool Steel No. 1 CARNEQIE STEEL CpMPANY 3. Where the grains are very coarse and bright. These areprogressively larger towards the melted end of the bar and show thegrowth in grain size which takes place when steels are heated abovethe hardening point. Maximum hardness occurs with minimum grain size.To insure this condition steels must be heated above thehardening point. The temperature should be held justabove this point to insure uniform heating throughout thebar, but beyond this point steel should not be heated morethan absolutely necessary. HARDENING POINT. The hardening temperature fortool steels (the point of minimum grain size) varies withthe chemical composition. In carbonless iron it occursat about 1697° F.;in steels of .90 carbon or over, at 1382° F.It is also affected by the presence of alloys. The line of minimum grain size for carbon steels ofdifferent composition is shown on the chart, Fig. 6. Com-panion, Fig. 5, Note About Images Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original work.", by Carnegie steel company. [from old catalog], 1918, licensed under No restrictions, via Wikimedia Commons. View source. View in tree.
• Toothbrush: "​宋朝牙刷 虎骨", by Aldermanseven, 2021, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Torpedo boat: "A illustration of HMS Lightning, a Torpedo boat in 1877.", by Author of article credited as "Mr. Donaldson", 1877, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Touchscreen: "There are 35 of these LCD touchscreens around the store. They're what let you access the 1 million+ songs that you can mix and burn. Each station has nice Bose headphones, an extra headphone jack, a barcode scanner, a card swiper, and of course, a touch screen.", by Thomas Duesing from Austin, TX, USA, 2005, licensed under CC BY 2.0, via Wikimedia Commons. View source. View in tree.
• Touchstone: "touchstone set", by jcw, 2011, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Tournette: "Dendera Temple complex", by Panegyrics of Granovetter, 2020, licensed under CC BY-SA 2.0, via Wikimedia Commons. View source. View in tree.
• Traction engine: "Aveling & Porter traction engine 'Avellana'", by Rob Mitchell, 2013, licensed under CC0, via Wikimedia Commons. View source. View in tree.
• Traction trebuchet: "Military Museum: Ancient Weapons", by Flickr user Gary Todd, 2008, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Tractor: "Dan Albone on his prototype Ivel Agricultural motor. Picture from North Bedfordshire Gazette, Friday, January 23, 1903.", licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Traffic light: "Installation of a traffic signal in San Diego, California.", by Russell Lee, 1940, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Transformer (machine learning): "Illustrations for the Transformer, and attention mechanism. Transformer, full architecture.", by dvgodoy, 2021, licensed under CC BY 4.0, via Wikimedia Commons. View source. View in tree.
• Transformer read-only storage: "IBM System 360/20 TROS.", by en:User:RTC, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Transistor: "In 1997 Lucent Technologies created this replica to commemorate the 50th anniversary of the invention of the point-contact transistor at Bell Labs in December 1947.", by Federal employee, 1997, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Transistor computer: "Creator: Dudley, Roger Description: The behavior of an elastic ball bounced on a hard surface is mathematically simulated by an w:IBM 1620 data processing system and visually traced by a CalComp digital plotter linked to the computer. This 'bouncing ball' problem is demonstrated daily in the 'Tools of Science' area of the U.S. Science Exhibit at the World's Fair. <a href="http://content.lib.washington.edu/u?/imlsmohai,3684" rel="nofollow">View source image</a>. Part of <a href="http://content.lib.washington.edu/imls/kcsnapshots/index.html" rel="nofollow">King County Snapshots</a> <a href="http://www.lib.washington.edu/" rel="nofollow">University of Washington Libraries</a>. Brought to you by <a href="http://imlsdcc.grainger.uiuc.edu/" rel="nofollow">IMLS Digital Collections and Content</a>. Unrestricted access; use with attribution.", by Roger Dudley, IMLS Digital Collections & Content, 1962, licensed under CC BY 2.0, via Wikimedia Commons. View source. View in tree.
• Transistor radio: "Emerson Model 888 Pioneer 8-Transistor AM Radio, Made in the USA, Circa 1958", by Joe Haupt from USA, 2015, licensed under CC BY-SA 2.0, via Wikimedia Commons. View source. View in tree.
• Transistorized electronic calculator: "Friden Model 132 calculator. The object in this image is within the permanent collection of The Children’s Museum of Indianapolis", by Friden Company, 1965, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Trautonium: "Volkstrautonium, Telefunken Berlin, 1933/1934 Musikinstrumentenmuseum Berlin, Kat.-Nr. 5264", by Museumsinsulaner, 2009, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Travois: "Blackfoot travois. Anthropological Papers of the American Museum of Natural History. Material culture of the Blackfoot Indians. 1910. Clark Wissler. p. 89", by Djembayz, 2012, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Treadwheel crane: "Reconstruction of a Roman crane", by Qualle, 2005, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Tricycle and quadricycle: "1876 Smith & Starley Coventry Lever Tricycle Taken at the British Motor Museum, Gaydon", by Vauxford, 2018, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Triode: "An early De Forest audion tube, the first electron tube that could amplify. The first triode, or tube with three electrodes, a filament, grid, and plate, the audion was invented in 1906 by American engineer Lee De Forest. The top metal electrode is the plate. The zigzag metal wire partly visible under it is the grid. The filament was originally under that, attached to the wires at left, but has burned out. As many Audions did, this model had two filaments (indicated by the four filament supply wires) so that when one burned out the "spare" could be used. The filament wires were attached to the screw terminal at left, while the grid and plate terminals were brought out through the right end of the glass envelope to the two wires at right. Tube belongs to History of San Jose, Perham Collection of Early Electronics.", by Gregory F. Maxwell <gmaxwell@gmail.com> PGP:0xB0413BFA, 2006, licensed under GFDL 1.2, via Wikimedia Commons. View source. View in tree.
• Trip hammer: "A set of trip hammers on an axle rotated by a waterwheel, a machine used to decorticate grain. From the Tiangong Kaiwu encyclopedia of 1637, written by the Ming Dynasty encyclopedist Song Yingxing (1587-1666).", by PericlesofAthens, 2007, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Trireme: "Roman trireme on the mosaic in Tunisia image taken by user:Mathiasrex Maciej Szczepańczyk", by Mathiasrex, 2006, licensed under CC BY 2.5, via Wikimedia Commons. View source. View in tree.
• Trompe: "Catalan forge", by Henry Hartshorne (1823-1897) (see [1] and [2]), 1881, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• True arch: "Magazine des Ramesseums nordwestlich von Luxor, Ägypten", by Olaf Tausch, 2019, licensed under CC BY 3.0, via Wikimedia Commons. View source. View in tree.
• True arch bridge: "Roma, ItaliaIMG_0838 Ponte Rotto", by Patrick Denker, 2006, licensed under CC BY 2.0, via Wikimedia Commons. View source. View in tree.
• True flintlock: "Musee-historique-lausanne-img 0086.jpg", licensed under CC BY-SA 2.0 fr, via Wikimedia Commons. View source. View in tree.
• Trumpet: "This trumpet includes the engraving of the name and image of Tutankhamun and those of three gods. The musician used the wooden mute painted in bright colours to modulate the sound of the trumpet.", by Suaudeau, 2019, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Tuned radio frequency receiver: "1920s TRF radio manufactured by Signal Electric MFG. CO. located in Menominee Mich. Demonstrates early radio construction methods using "breadboard"", by Armstrong1113149, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Tungsten: "Tungsten rods with evaporated crystals, partially oxidized with colorful tarnish. Purity 99.98 %, as well as a high pure (99.999 % = 5N) 1 cm3 tungsten cube for comparison.", by Alchemist-hp (talk) (www.pse-mendelejew.de), 2010, licensed under FAL, via Wikimedia Commons. View source. View in tree.
• Tungsten filament: "Tungsram tungsten light bulb advertisement in 1906. The inscription reads: "Wire lamp with a drawn wire – indestructible!", by Tungsram Copmpany, 1906, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Tunnel boring machine: "The southern shield in the intersection chamber.", by The original uploader was Tambo at Hungarian Wikipedia., 2010, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Tunnel diode: "1N3716 tunnel diode made by GE, with 0.1" jumper in the background for scale", by Caliston, 2008, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Tunnelling shield: "Diagram of the tunnelling shield used to construct the Thames Tunnel, London.", licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Turbofan: "Rolls-Royce Conway turbofan engine on display at the East Midland Aeropark.", by Nimbus227, 2022, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Turbojet: "Took this by Distractxreact at the National Air and Space Museum with a Canon PowerShot A510. This is a Junkers Jumo 004 as equipped to a Messerschmidt Me-262.", by Original uploader and author was Distractxreact at en.wikipedia, 2007, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Turing machine: "Turing Machine, reconstructed by Mike Davey as seen at Go Ask ALICE at Harvard University", by Rocky Acosta, 2012, licensed under CC BY 3.0, via Wikimedia Commons. View source. View in tree.
• TV remote control: "World's 1st wireless TV remote control", by Edd Thomas from UK, 2017, licensed under CC BY 2.0, via Wikimedia Commons. View source. View in tree.
• Typewriter: "Schreibkugel von Hans Rasmus Johann Malling Hansen 1878", by Eremeev, 2016, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Typewriter with QWERTY keyboard: "Schreibmaschinenausstellung im Deutschen Museum", by Burkhard Mücke, 2023, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Tyrian purple: "Natural silk dyed with Hexaplex trunculus pigment from Carthage", by Tyrargaman, 2015, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Ultracentrifuge: "Beckman-Coulter ultracentrifuge, XL-100K", by real name: Matylda Sęk pl.wiki: Cygaretka commons: Cygaretka, 2011, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Ultramarine: "Natural ultramarine pigment.jpg", licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Ultramicroscope: "Invention of the ultramicroscope by Henry Siedentopf and Richard A. Zsigmondy; In 1903 Ernst Abbe retires from the management, handicapped by severe health problems. He lives to see in this year the limits of classical microscopy finally exceeded by the ultramicroscope, an invention by Henry Siedentopf and Richard Zsigmondy, which makes submicroscopical colloids visible. This is actually the first published account of a very simple version of a light sheet fluorescence microscope (or LSFM) in which light of an arc lamp was projected through a slit aperture to observe gold particles.", by ZEISS Microscopy from Germany, 2012, licensed under CC BY-SA 2.0, via Wikimedia Commons. View source. View in tree.
• Umami: "A small bowl of soy sauce with a blob of green wasabi paste on the side and chop sticks laid across the top.", by Melissa Doroquez, 2008, licensed under CC BY-SA 2.0, via Wikimedia Commons. View source. View in tree.
• Universal Standard Time: "French World map showing the time zones of the world", by Ministère de la marine, 1939, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Uranium: "Yellowcake.jpg", licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Uranium-235: "A billet of highly enriched uranium that was recovered from scrap processed at the Y-12 National Security Complex Plant. Original and unrotated.", by Unspecified, 1996, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Usenet: "Slrn.png", licensed under GPL, via Wikimedia Commons. View source. View in tree.
• V8 engine: "Motore aeronautico Antoinette, esposto al Museo nazionale della scienza e della tecnologia Leonardo da Vinci di Milano.", by Alessandro Nassiri for Museo scienza e tecnologia Milano, 2013, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Vacuum flask: "Pictures taken at the museum part of the Royal Institution building at 21 Albemarle St", by Vera de Kok, 2014, licensed under CC BY 4.0, via Wikimedia Commons. View source. View in tree.
• Vacuum fluorescent display: "A vacuum fluorescent display from an entirely-typical VCR (video cassette recorder).", by No machine-readable author provided. Atlant assumed (based on copyright claims)., 2006, licensed under CC BY 2.5, via Wikimedia Commons. View source. View in tree.
• Vacuum pan: "Mounted Calotype depicting a scene from the Great Exhibition of 1851. From Henry Fox Talbot's presentation report, Spicer Brothers, Wholesale Stationers, W. Clowes & Sons, Printers, 1852.", by William Henry Fox Talbot, 1851, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Vacuum pump: "von Guericke's 1st Air Pump, Experimenta Nova (ut vocantur) De Vacuo Spatio (1672) Fig. 1, p. 74.", by Ottonis de Guericke, 1672, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Van de Graaff generator: "Van de Graaff generator for schools", by Zátonyi Sándor, (ifj.) Fizped, 2013, licensed under CC BY 3.0, via Wikimedia Commons. View source. View in tree.
• Vanilla hand-pollination: "Edmond Albius inventeur de la fécondation artificielle du vanillier. Image composée d'après Antoine Louis Roussin et d'une fleur de vanille.", by Ambre Troizat, 2015, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Vapor-compression refrigeration system: "Diagram of John Gorrie's Ice Machine. From U.S. Patent 8080, May 6, 1851.", licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Variolation: "A hand with three smallpox pustules. Coloured etching by W. Cuff and W. Skelton after himself. Iconographic Collections Keywords: William Skelton; Smallpox; pustules", licensed under CC BY 4.0, via Wikimedia Commons. View source. View in tree.
• Vending machine: "Ancient vending music, Kotsanas Museum of Ancient Technology, Athens, Greece", by Denexeitelos, 2025, licensed under CC BY 4.0, via Wikimedia Commons. View source. View in tree.
• Ventilator: "Medical ventilator Bird Mark 8", by Stefan Bellini, 2015, licensed under CC0, via Wikimedia Commons. View source. View in tree.
• Verge escapement and foliot: "Verge and foliot from De Vick's clock", by Unknown authorUnknown author, 1911, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Verneuil method: "Synthetic Corundum produced according to the Verneuil-procedure", by U.Name.Me, 2018, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Vernier scale: "Messschieber, für Übungen zum Ablesen des Nonius, nur in kleinen Schritten - von Bild zu Bild - verstellt", by Bin im Garten, 2018, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Video camera tube: "One of the first experimental video camera tubes, called an image dissector, designed by American engineer Philo T. Farnsworth in 1930.", by Philo T. Farnsworth, 1931, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Video game: "Schematic showing a 3-bit adder using Additron tubes, as per the patent filing", by Josef Kates, 1951, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Video game console: "The Magnavox Odyssey, the very first video game console. Released in 1972, the Odyssey was a simple and crude device that generated shapes on the television that could be controlled and interacted with. It only produced black and white graphics and had no sound, but was limited to only using discrete components like diodes and transistors. It was replaced in 1975 with the Magnavox Odyssey series, a line of dedicated Pong consoles.", by Evan-Amos, 2015, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Video tape recorder: "First Video Recorder. Ampex videotape recorder, type VR1000A, serial number 329, c 1950s. Credit: Science Museum Inventory No.: 1970-0173_(0001)", by Karl Baron from Lund, Sweden, 2006, licensed under CC BY 2.0, via Wikimedia Commons. View source. View in tree.
• Videocassette recorder: "U-matic tape. Photo taken by grm_wnr on day of uploading.", by No machine-readable author provided. Grm wnr assumed (based on copyright claims)., 2005, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Videotex: "Entry page for first version (1983) of messaging service on Prestel, a former British public videotex service.", by Protalina, 1983, licensed under CC0, via Wikimedia Commons. View source. View in tree.
• Vielle: "Folio 130r miniado del Beati in Apocalipsin libri duodecim. Vitr-14/1. Escritura visigótica. 144 folios en pergamino a 2 columnas, de 33 a 35 líneas por página. Miniatura mozárabe. Procedente de la biblioteca de Serafín Estébanez Calderón y de San Millán de la Cogolla. In English the page describing the work is Commentary on the Apocalypse", by Beato_Vitr14-1_Fol130r.jpg: Beato de Liébana, factor anónimo derivative work: Escarlati (talk), 2011, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Vihuela: "Musician playing a vihuela in the Borgia Apartments (Vatican)", by Pinturicchio, 1492, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Vinyl: "A pure, raw form of polyvinyl chloride, without any plasticizer", by LHcheM, 2012, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Vinyl record: "Rare Columbia 7 inch vinyl 33 1⁄3 rpm microgroove ZLP from 1948", by DigbyDalton, 2016, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Viola da gamba: "Front and side of a viola da gamba", by https://commons.wikimedia.org/w/index.php?title=Creator:Richard_Meares&action=edit&redlink=1, 2017, licensed under CC0, via Wikimedia Commons. View source. View in tree.
• Violin, viola, and cello: "Viola da braccio en un fresco de Gaudenzio Ferrari en Santa Maria dei Miracoli", by Gaudenzio Ferrari, 1535, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Visible-light LED: "5 mm Red LED (on).", by oomlout, 2013, licensed under CC BY-SA 2.0, via Wikimedia Commons. View source. View in tree.
• Visual receptive field: "Gabor filter", by w:en:user:Joe pharos, 2006, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Vocoder: "Early 1970's transistor vocoder custom built and used by the electric band Kraftwerk for the album Ralf und Florian - Now in possession of Daniel Miller (music producer)", by GoodOmens at English Wikipedia, 2006, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Volley gun: "Ribauldequin (or organ gun), 15th century, studies from Leonardo da Vinci.", by Leonardo da Vinci, 1450, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Voltaic pile: "pila di volta", by Markkv, 2021, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Von Neumann architecture: "von Neumann Architecture", by Kapooht, 2013, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Vulcanized rubber: "Worker operating an automatic vulcanization mold at Firestone (General) Tires, Akron, Ohio. The mold is closed by pushing a button, which starts several operations. First the airbag is filled with live steam which circulates during the entire process; next an automatic timer sets itself for the proper length of time and temperature; next pressure is exerted to squeeze the tire into the mold pattern.", by Alfred T. Palmer, 1941, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Wagonway: "Diolkos", by Davide Mauro, 2018, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Walkie-talkie: "SCR536 US Signal Corps "Walkie Talkie"", by Unknown authorUnknown author, 2008, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• War wagon: "Replica of a Hussite war wagon (Chudów, Poland)", by Ludek, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Warp knitting frame: "Nottingham Industrial Museum", by ClemRutter, 2017, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Washing machine: "1766 illustration of a washing machine invented by Jacob Christian Schäffer.", by Jacob Christian Schäffer, 1766, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Water clock: "Klepsydra - Water Clock: Reconstruction of a clay original of the late 5th cent. B.C. Ancient Agora Museum in Athens.", by Marsyas, licensed under CC BY-SA 2.5, via Wikimedia Commons. View source. View in tree.
• Water frame: "Arkwright_Spinning_frame:This was the precursor to the Water Frame. Images from Marsden 1884 book on Cotton Spinning.", by Unknown authorUnknown author, 1884, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Water organ: "Mosaïque de Zliten", by The original uploader was Nacéra Benseddik at French Wikipedia., 2010, licensed under CC BY-SA 1.0, via Wikimedia Commons. View source. View in tree.
• Water turbine: "Vertical axle watermill at Chemtou, Tunisia c.114 AD. The date is taken from the inscription CIL VIII, 10117. While the inscription was not attached to this structure, it is reasonably sure that the two are related.", by Sheredot, 2008, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Water wheel (China): "Two illustrations of Chinese hydraulic-powered chain pumps. The top illustration shows a horizontal waterwheel acting upon a horizontal and vertical wheel and axle that rotates a square-pallet chain pump bringing water from a stream up to the irrigation canal. The bottom illustration shows a vertical waterwheel as part of a cylinder-wheel chain pump bringing water up from a river to an irrigation canal of a crop field. These illustrations were printed in the Tiangong Kaiwu encyclopedia of 1637, written by the Ming Dynasty encyclopedist Song Yingxing (1587-1666). They can be found on pages 15 and 18 of E-tu Zen Sun and Shiou-Chuan Sun's English translation of the Tiangong Kaiwu (Pennsylvania University State Press, 1966). This image was taken from http://www.chinawater.net.cn/kjcg/CWSArticle_View.asp?CWSNewsID=17233", by Unknown authorUnknown author, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Water wheel (Greece): "The "Brucker Wasserrad", a noria in Bruck, a district of Erlangen, Germany, at work for about one minute.", by Spike, 2020, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Water-driven astronomical clock: "File:Clock_Tower_from_Su_Song's_Book.JPG with smear removed by mixing channels: Red: 0.2 green + blue Green: 0.4 green + 0.65 blue Blue: blue as red is badly smeared, green is slightly smeared but has least noise, and blue is not smeared but has most noise.", by Su Song, 2007, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Water-powered blast furnace: "This medieval printed illustration depicts waterwheels powering the bellows of a blast furnace in creating cast iron. This illustration is taken from the 14th century treatise Nong Shu, written by Wang Zhen in 1313 AD, during the Chinese Yuan Dynasty.", by Wang Zhen, 1313, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Waterproof concrete: "Bloczek betonowy.", by Ablazejo, 2014, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Watt steam engine: "A beam engine of the Watt type, built by D. Napier & Son (London) in 1832. It drove the coining presses of the Royal Spanish Mint from 1861 to 1891. In 1914 it was donated to the Higher Technical School of Industrial Engineering of Madrid (part of the UPM) and installed in its lobby.", by Nicolás Pérez, 2004, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Wave–particle duality of matter: "One of a set of twenty copies of original electron diffraction photographs https://collection.sciencemuseumgroup.org.uk/objects/co5292/set-of-twenty-copies-of-original-electron-diffraction-photographs-photograph", by Image and original data from Science Museum Group Set of twenty copies of original electron diffraction photographs. 1948-190, 2012, licensed under CC BY 4.0, via Wikimedia Commons. View source. View in tree.
• Wax tablet: "Writing tablet with wax and stylus. Roman period. The sharp tip was used for writing and the flat end was for wiping it out.", by Peter van der Sluijs, 2012, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Weather forecasting: "Weather map of Europe (09. & 10 December 1887)", by Public domain works must be out of copyright in both the United States and in the source country of the work in order to be hosted on the Commons. If the work is not a U.S. work, the file must have an additional copyright tag indicating the copyright status in the source country.Note: This tag should not be used for sound recordings.PD-1923Public domain in the United States//commons.wikimedia.org/wiki/File:Meyers_b16_s0570.jpg, 1885, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Weathering steel: "Texture of a sheet of Cor-Ten after being exposed to the elements for 5 years. The rust can form unevenly based on the composition of the metal.", by AndrewHenkelman, 2022, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Weaving: "Two women weaving linen on a horizontal loom", by Patrick Gray, 2015, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Web browser: "Screenshot of Netscape Navigator 4.51 on an SGI Indy running Irix 6.2", by Aeroid, 2019, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Western concert flute: "Theobald Böhm (1794-1881)", by Franz Hanfstaengl, 1852, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Whale oil: "Photo by Jeff Allen. Whale Oil", by Asknha1894, 2012, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Wheel: "Ljubljana Marshes Wheel with axle (oldest wooden wheel yet discovered)", by Petar Milošević, 2020, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Wheelbarrow: "Exhibit in the Sichuan Provincial Museum (四川省博物院), also known as the Sichuan Museum, 251 Huanhua S Road, Chengdu, Sichuan, China. Photography was permitted in the museum without restriction. This work is old enough so that it is in the public domain.", by Daderot, 2015, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Wheelchair: "Confucius and children. Note the handcart that is used to transport the sage - presumably, the mode of transport familiar to the early-Qing (1680) artist", by An unknown Chinese artist, 1680, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Wheellock: "Wheellock pistol.", by anonymous, 1675, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• White LED: "5 mm Tinted White LED (on).", by oomlout, 2014, licensed under CC BY-SA 2.0, via Wikimedia Commons. View source. View in tree.
• White phosphorus match: "Match-making was a particularly dangerous job in the 1800s. Workers – mainly women – employed by companies such as Bryant & May to make matches commonly experienced a condition known as phossy jaw. This was caused by poisoning from the yellow phosphorous used in the head of the match. Phossy jaw was a terribly disfiguring and sometimes fatal condition. Eventually, a combination of this health danger, poor pay and long hours led to the formation of a trade union for the workers. The Match Girls Strike of 1888, led by social activist Annie Besant (1847-1933), was a landmark industrial action and led to better pay. In 1901, Bryant & May finally stopped using yellow phosphorous in their matches. maker: Bryant and May Place made: Bow, Tower Hamlets, London, Greater London, England, United Kingdom Wellcome Images Keywords: match box; phossy jaw", licensed under CC BY 4.0, via Wikimedia Commons. View source. View in tree.
• White phosphorus munition: "Night attack with phosphorus bombs in maneuvers. First Corps School. Gondrecourt, France.", by US Gov., 1918, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Whiteprint: "Альбом с чертежами, копии которого сняты при помощи процесса диазотипии (на жаргоне "синька"). Также по этому процессу изготовлены наклейки на обложке с альбомами документации. Процесс диазотипии часто использовался для выпуска документации малыми тиражами.", by инженер Павел Серков, 2020, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Wi-Fi: "Logo", by Unknown authorUnknown author, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Wide-area computer network: "ARPANET logical map circa 1977", by ARPANET, 1977, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Wiki: "A screenshot of Wikipedia's wiki markup article (slightly modified to show what wikitext essentially means) in edit/preview mode (using MediaWiki 1.16 with default Vector skin)", by (text: main parts written by Andrewa in November 2004, cf. history, adapted later by several other users), 2010, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Williams tube memory: "A Williams tube", by Sk2k52, 2007, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Wimshurst influence machine: "A Wimshurst machine, an electrostatic generator which generates high voltage static electricity with two counterrotating disks turned by a crank.", by No machine-readable author provided. Peedl~commonswiki assumed (based on copyright claims)., 2006, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Wind turbine: "Blyth's wind turbine built to power the lighting at his summer home in Marykirk, Scotland. This is not his first wind turbine, however.", by Unknown authorUnknown author, 1891, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Winepress: "Wine press in Shivta", by ד"ר אבישי טייכר, 2011, licensed under CC BY 2.5, via Wikimedia Commons. View source. View in tree.
• Wire recording: "Magnetic wire recorder, invented by Valdemar Poulsen, 1898. It is exhibited at Brede works Industrial Museum, Lingby, Danmark.", by Original uploader was Bitman at hu.wikipedia, 2009, licensed under CC BY-SA 2.5, via Wikimedia Commons. View source. View in tree.
• Wire wheel: "Coventry Transport Museum, UK. 2009", by ...some guy, 2009, licensed under CC BY 2.0, via Wikimedia Commons. View source. View in tree.
• Wireless computer network: "An icon to indicate: Wi-Fi, Wireless LAN, a hotspot, an access point, or a broadcast", by RRZEicons, 2008, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Wireless telegraphy: "New Guinea. Radio Operator, Cpl. John Robbins of Louisville, Nebraska, 41st Signal, 41st Inf. Div., operating his SCR 188 radio in a sandbagged hut at Station NYU. Dobodura, New Guinea. He is transmitting by radiotelegraphy tapping on a telegraph key which turns the transmitter on and off, transmitting pulses of radio waves which spell out a text message in Morse code. Signal Corps Photo: GHQ SWPA SC 43 5901 (T/4 Harold Newman)", by Photograph was taken by the U.S. Army Signal Corps, photo number: GHQ SWPA SC 43 5901 by T/4 Harold Newman., 1943, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Wirephoto: "Belinograph-CnAM 18774-IMG 5328-gradient.jpg", by Rama, 2018, licensed under CC BY-SA 3.0 fr, via Wikimedia Commons. View source. View in tree.
• Wood gas and thermolamp: "Phlippe Lebon's oven", by Philippe Lebon, 1899, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Woodblock printing: "Frontispiece, Diamond Sutra from Cave 17, Dunhuang, ink on paper. A page from the Diamond Sutra, printed in the 9th year of Xiantong Era of the Tang dynasty, i.e. 868 CE. Currently located in the British Library, London. This sutra was discovered at the Mogao Caves in Dunhuang, but probably printed in Sichuan (see "Printed dated copy of the Diamond Sutra"). According to the British Library, it is “the earliest complete survival of a dated printed book”. British Library Or.8210/P.2", by The colophon, at the inner end, reads: Reverently [caused to be] made for universal free distribution by Wang Jie on behalf of his two parents on the 13th of the 4th moon of the 9th year of Xiantong [i.e. 11th May, CE 868 ]., 0868, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Word processor software: "Screenshot von WordStar 3.0", by --Plenz 20:42, 19. Jul 2004 (CEST), 2004, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• World map: "A close-up view of the Babylonian map of the World. This partially broken clay tablet contains both cuneiform inscriptions and a unique map of the Mesopotamian world. Probably from Sippar, Mesopotamia, Iraq. 700-500 BCE. The British Museum, London.", by Osama Shukir Muhammed Amin FRCP(Glasg), 2014, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• World Wide Web: "WWW's "historical" logo, created by Robert Cailliau in 1990. Made of three W using the Optima Bold font, according to Cailliau himself.", by Fakefunk, 2022, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Worm drive roller gin: "Neuthoni (নেওঠনি) is a traditional Assamese equipment that is used to separate raw cotton from its seeds.", by Chiring chandan, 2021, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• Wristwatch: "Schuetzengrabenarmbanduhr, Waltham, USA, um 1914 (Deutsches Uhrenmuseum, Inv. 47-3352)", by Museumsfoto, 2011, licensed under CC BY 3.0 de, via Wikimedia Commons. View source. View in tree.
• Writing (China): "Oracle bone from the Bīn 賓 group of diviners from period I, corresponding to the reign of King Wu Ding (late Shang dynasty).", 1200, licensed under CC0, via Wikimedia Commons. View source. View in tree.
• Writing (Egypt): "Fragment of a wall with hieroglyphs from the tomb of Seti I (reign c.1294 or 1290 - 1279 BC)", by unknown Egyptian scribe, 2007, licensed under Copyrighted free use, via Wikimedia Commons. View source. View in tree.
• Writing (Mesoamerica): "A drawing of the Cascajal block. This high-resolution image was drawn by me, based loosely on a the low-resolution greyscale image published by "Science" and re-published by a number of other news providers, such as the "National Geographic".", by Cascajal-text.jpg: Michael Everson derivative work: Jon C (talk), 2012, licensed under CC BY 3.0, via Wikimedia Commons. View source. View in tree.
• Writing (Mesopotamia): "Sumerian; Cuneiform tablet; Clay-Tablets-Inscribed-Seal Impressions", 3100, licensed under CC0, via Wikimedia Commons. View source. View in tree.
• X-Acto knife: "An X-Acto knife that uses size 2 blades. Shown with extra blade.", by Evan-Amos, 2010, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• X-ray: "Hand mit Ringen (Hand with Rings): a print of one of the first X-rays by Wilhelm Röntgen (1845–1923) of the left hand of his wife Anna Bertha Ludwig. It was presented to Professor Ludwig Zehnder of the Physik Institut, University of Freiburg, on 1 January 1896.", by Wilhelm Röntgen, 1895, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• X-ray crystallography: "X-Ray crystallography is a tool used for identifying the atomic and molecular structure of a crystal. The movement of the machine during 80 second scan can give different view on how relatively slow scientific measurements can look frozen in time by shutter speed of 90 seconds.", by Kaspar Kallip, 2015, licensed under CC BY-SA 4.0, via Wikimedia Commons. View source. View in tree.
• X-ray tube: "Drawing of a Crookes type x-ray tube made by Alfred Cossor, from the early 1900s. The caption text: 'A Cossor bulb with automatic softening device and fin radiator for cooling anticathode.' Alterations to image: cropped out caption. The electrode on the right is the aluminum cathode, which focuses a beam of electrons on a small (~1 mm) spot on the angled platinum anode target, called the 'anticathode', in the center of the bulb, creating x-rays. The anticathode is angled so the x-rays are radiated downwards, passing out through the glass side wall of the tube. The electrode at the 10 o'clock position is called the auxiliary anode. The sausage-shaped device at the top is an 'automatic softener' to control the pressure in the tube. Crookes type tubes required some gas in the tube to operate, but with time the residual gas was absorbed and the vacuum in the tube increased, requiring a higher potential to operate, generating 'harder' x-rays, until eventually the tube stopped operating. The 'softener' prevents this. When the pressure drops and the voltage across the tube increases, the anode potential arcs across the spark gap to the softener electrode, and the current heats the helical sleeve in the softener, which releases gas, raising the pressure in the tube. Alfred Charles Cossor's workshop in Clerkenwill, London was at that time the only British manufacturer of Crookes x-ray tubes. These cold cathode x-ray tubes were used until the 1920s.", by George William Clarkson Kaye, 1914, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Xenon: "Spectrum = gas discharge tube: the noble gas: xenon Xe. Used with 1,8kV, 18mA, 35kHz. ≈8" length.", by Alchemist-hp (talk) (www.pse-mendelejew.de), 2006, licensed under FAL, via Wikimedia Commons. View source. View in tree.
• Xun lei chong: "Ming dynasty 5-barreled firearm with a flamethrower and a spear head on center shaft."迅雷銃" mean "fast-thunder gun".", by 趙士楨, 1598, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Xylophone: "The kulintang a kayo is a Philippine xylophone with eight tuned slabs arranged horizontally atop a wooden antangan (rack). This instrument in particular is used by Master Danongan Kalanduyan at San Francisco State University to teach his kulintang class.", by Philip Dominguez Mercurio (PhilipDM), 2006, licensed under CC BY-SA 2.5, via Wikimedia Commons. View source. View in tree.
• Yablochkov candle: "In 1878 the Victoria Embankment (near Westminster Bridge), which was previously lit by gas, was illuminated with Jablochkoff Candle arc light alternating with the original gas standards to show the difference. Supply came from Gramme AC generators. The prime movers were steam engines made by Ransomes, Sims and Head of Ipswich. In June 1884, gas lighting was re-established as electricity was not competitive. The original lighting standards are still in situ.", by Unknown illustrator, 1878, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Yagi–Uda antenna: "A television antenna from a 1954 advertisement by the Radiart Corp., Cleveland, Ohio. It is a Yagi-Uda antenna for use on the 'low band' analog channels 2-4, 47 - 68 MHz. It has three director elements (crossbars on left) and one reflector (crossbar on right), and it's direction of greatest sensitivity (main lobe) is of the end of the antenna to the left. The driven element is a folded dipole to match the 300 ohm twin lead feedline to the TV set. The antenna is made of aluminum tubing, the elements are roughly 6 feet across. Changes to image: Cropped out advertising copy and adjacent intruding images, redrew minor areas in image that were smudged through poor copying.", by Unknown authorUnknown author, 1954, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Yakhchāl: "Yakhchal of Yazd province", by Pastaitaken, 2008, licensed under CC BY-SA 3.0, via Wikimedia Commons. View source. View in tree.
• Yale pin-tumbler lock: "Yale lock, as pictured in Otto's Encyclopedia (Ottův slovník naučný, 1908).", by Unknown authorUnknown author. The author of the picture is not given, but it is possible that it is Josef Pokorný, the author of the text of the encyclopedia entry., 2014, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Yellow LED: "5 mm Tinted Yellow LED (on).", by oomlout, 2014, licensed under CC BY-SA 2.0, via Wikimedia Commons. View source. View in tree.
• Yttrium: "Yttrium, sublimed-dendritic, high purity 99.99 % Y/TREM. As well as an argon arc remelted 1 cm3 yttrium cube for comparison. Purity 99.9 %.", by Alchemist-hp (www.pse-mendelejew.de), 2010, licensed under FAL, via Wikimedia Commons. View source. View in tree.
• Zeppelin: "USS Los Angeles (ZR-3) moored to USS Patoka, off Panama during the winter of 1931.", by USN, 1931, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Zinc smelting: "zinc, purity 99.995 %, left: a crystaline fragment of an ingot, right: sublimed-dendritic, and a 1 cm3 zinc cube for comparison.", by Alchemist-hp (talk) (www.pse-mendelejew.de), 2010, licensed under FAL, via Wikimedia Commons. View source. View in tree.
• Zippe-type centrifuge: "Zippe-type gas centrifuge.svg", licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Zipper: "Whitcomb Judson "clasp locker" patent 1893 - precurser to the modern zipper.", by United States Patent Office, 1893, licensed under Public domain, via Wikimedia Commons. View source. View in tree.
• Zirconium: "Purest zirconium 99.97%, two samples of crystal bar showing different surface textures, made by crystal bar process, as well as a highly pure (99,95 % = 3N5) 1 cm3 zirconium cube for comparison. The metal piece-photo was taken on a white glass plate.", by Alchemist-hp (pse-mendelejew.de)., 2011, licensed under FAL, via Wikimedia Commons. View source. View in tree.
• Zoopraxiscope: "Zoopraxiscope 16485u.jpg", licensed under Public domain, via Wikimedia Commons. View source. View in tree.