1902 Lockwood's Dict. Mech. Engin. (ed. 3) Flash Boiler, a rapidly steaming boiler in which the steam is generated in coils of small tubes.

1906 Daily Chron. 3 Mar. 3/6 Water is converted into steam in a tubular boiler, called a flash boiler.

1940 Flight 26 Dec. b/2 Flash bombs are dropped to illumine the target.

1935 News Chron. Amateur Photogr. ii. iii. 200 The flashlight need not be situated directly behind the camera..particularly if a flash-bulb is available.

1937 Pop. Sci. Monthly Aug. 86/1 (heading) Using two flash bulbs for portrait photos.

1937 Pop. Sci. Monthly Aug. 86/1 Any flash-bulb holder, operated by batteries, may be easily adapted.

1939 K. Henney & B. Dudley Handbk. Photogr. iv. 93 Synchronized flash guns are devices which enable the photographer to fire off a flash bulb at the same instant the shutter of his camera is opened.

1954 X. Fielding Hide & Seek ix. 113 Half a dozen sheep stood there motionless for a second, as though posing for a flash-bulb photograph.

1946 Nature 3 Aug. 152/1 An attack by atomic bombs would, no doubt, cause some casualties by ‘flashburn’, although even ordinary clothing appears to offer substantial protection against it.

1951 Ann. Reg. 1950 420 The three major effects [of atomic warfare] were blast, flash-burn, and radiological.

1933 Welding Ind. Aug. 224/2 On flash butt welding machines, the transformer if inside the housing is exposed to the damage which may be caused by the unavoidable considerable sparking.

1958 A. D. Merriman Dict. Metall. 95/1 Flash-butt welding, a resistance welding process in which an arc is struck and maintained between the joint members until welding heat is attained. The current is then shut off and the weld made by forcing the parts together.

1959 Jrnl. Iron & Steel Inst. 192 401/2 Flash welds gave the highest and most consistent results.

1933 Welding Ind. Feb. 4/1 Butt welding may be divided into (a) direct or upset method... (b) flash welding, in which the material is brought together and an arc is drawn between the parts to be welded. This arc plays along the material in a continuous flash and the pieces are moved together during this flashing period and when in the plastic state the current is interrupted and pressure applied.

1943 Jrnl. Royal Aeronaut. Soc. 47 289 Flash welding is a type of butt weld in which the two parts to be joined are connected to the secondary terminals of a low-voltage high-current transformer, are then brought into close proximity, and the voltage applied.

1923 Cumulative Book Index Apr. 18 Flash cards for rapid word drills.

1945 C. V. Good Dict. Educ. 173/2 Flash card, a small card of heavy cardboard having on it written or printed letters, words, phrases, numerals, or combinations of numerals for computation; used as an aid to learning, the teacher holding each card up for the class to see for a brief interval.

1953 W. A. Wittich & C. F. Schuller Audio-visual Materials iii. 53 Flash cards..ultimately create relationships and understandings of the symbols and the objects for which these symbols stand.

1964 Listener 12 Nov. 775/2 The raising of children's ‘flash-cards’: what do you think of this?—two seconds to answer.

1928 T. H. Savory Biol. Spiders viii. 160 Coloration may assist concealment..by the exhibition of the so called flash-colours.

1935 T. H. Savory Spiders Brit. Isles 28 When the spider has been disturbed and is running away, these quickly moving bright joints are conspicuous. But suddenly it stops and draws in its legs: the bright colours are hidden, and the spider becomes almost invisible—a method of protection known as ‘flash-colouring’.

1965 Perspective VII. 244/2 Multiple flash bulb, a so-called flash cube introduced for a low-priced amateur still camera consists of four tiny blue flash bulbs set in their own reflectors in four faces of a cube.

1967 Boston Sunday Herald 30 Apr. vi. 8/5 The Retina S-1 camera, designed to use flashcubes.

1977 J. Hedgecoe Photographer's Handbk. 24 The most basic peel-apart film cameras..offer scale focusing, a flash cube mounting, and usually have automatic exposure control.

1985 N.Y. Times 12 May i. 59/1 The Minox LX..has a built-in exposure meter and a flashcube attachment.

1950 Time 26 June 10 Big heating ovens..flash-dry the ink almost instantly.

1960 Times 20 Sept. (Pure Food Suppl.) p. xx Because the food is flash-dried in a high vacuum the moisture takes nothing away with it.

1946 Nature 10 Aug. 194/1 Considerable progress had been made in drying; and spray-drying, flash-drying and drum~drying have been developed with considerable success.

1940 Words Apr. 55/1 Harry Burns..died in a ‘flash’ flood which raced down Wheeling creek.

1963 N. Freeling Gun before Butter ii. 79 Flash floods of eleven centimetres of rain in an hour and a half.

1939 Nature 17 June 1028/1 A two feet deep band of boulders and sand, deposited in a period of flash flooding.

1632 W. Lithgow Totall Disc. Trav. viii. 339 Let not surmisers thinke, ambition led My second toyles, more flash-flowne praise to wed.

1888 Lockwood's Dict. Mech. Engin. Flash Flue, the flue underneath an egg-end or similar externally fired boiler.

1973 Publishers Weekly 26 Feb. 122/3 Kiley is shot during a student riot, but since he happens to be close to a friend's cryogenic lab, he is immediately flash-frozen.

1976 National Observer (U.S.) 12 June 1/1 Their clothes..look flash-frozen out of the '50s.

1984 Tampa (Florida) Tribune 28 Mar. 17 c/10 (advt.) Restaurant equip. for sale;..dbl refrig., flash freezer, ice cream machine [etc.].

1942 Woolrich & Bartlett Quick & Flash Freezing of Foods 13 This led to the discovery of ‘polyphase freezing’ or what some prefer to call ‘flash freezing’.

1968 New Scientist 29 Aug. 436/2 Any temperature between −120°C and −196°C can be produced in the flash-freezing section. The flash-freezing process can be fully controlled within that temperature range.

1984 N.Y. Times 9 Apr. c11/2 Flash freezing of fish at temperatures approaching 40 below zero lengthens their shelf life appreciably.

1977 Time 23 May 54/1 Passengers doze over their drinks, eat flash-frozen steaks.

1903 Work 28 Feb. 58/3 The cylinder constituting alternately a gas-engine and a flash generator.

1913 W. E. Dommett Motor Car Mech. 141 Flash generators are really a particular case of water-tube boilers, in which the tubes serve not only for the production of steam but simultaneously act as super~heaters.

1930 Pop. Sci. Monthly July 46/3 (caption) New flash gun and camera which it clicks, at the instant trigger fires flashlight cartridge.

1959 Which? May 25/2 The cameras tested could be used with flashguns—an advantage for anyone wanting to take indoor pictures.

1890 W. E. Woodbury Encycl. Photogr. 373 The electric lamp, magnesium lamp, and flash lamp.

1891 H. L. Webb in Electr. in Daily Life, Making a Cable 188 Flag-signalling had to be exchanged for flash-lamps.

1908 Model Engin. & Electrician 11 June 570/2 Flashlamp batteries.

1914 G. W. Young From Trenches xi. 234 Electric flash-lamps.

1928 Daily Express 11 Oct. 8 Tom shone his flashlamp on the knife.

1886 Sci. Amer. LIV. 16/2 A flash-light, that is to say, one which can be made to glow or disappear at pleasure.

1890 W. E. Woodbury Encycl. Photogr. 289 Flashlight, usually made by blowing magnesium powder through a small flame.

1892 M. Stokes Six Months in Apennines 163 I was compelled to photograph these most interesting bas-reliefs by the flash~light.

1901 Field & Stream Jan. 774/2 The Comet Baby Flash Light.

1902 A. Bennett Grand Babylon Hotel xiii. 144 Rocco had photographed the corpse by flashlight.

1906 Westm. Gaz. 19 Mar. 3/1 To attempt to flashlight him at night is an invitation..to trample the photographer and his camera into a jumble of mutilated fragments.

1917 R. Kipling Diversity of Creatures 205 We were studying the interior of a soul, flash-lighted by the dread of ‘losing its position’.

1919 F. Hurst Humoresque 233 A gold-handled umbrella with a bachelor-girl flash-light attachment.

1940 E. Caldwell Trouble in July xii. 179 Several men rushed inside, flashlighting the room.

1958 ‘A. Gilbert’ Death against Clock 65 Carry a flash~light by any chance?

1959 H. Barnes Oceanogr. & Marine Biol. 183 Electronic flash-lighting with a G.E.C. flash-tube is again employed, the camera mechanism being synchronized to the flash.

1957 D. T. Herman et al. in S. Saporta & J. R. Bastian Psycholinguistics (1961) 538/2 A Keystone Model 1045 projector equipped with an Ilex flashmeter was used.

1959 J. W. Brown et al. A-V Instructional Materials Man. iv. 157 Keystone overhead projector setup, with tachistoscope (flash meter) and mask in place, ready to project reading slides.

1921 M. Mortenson Managem. Dairy Plants xi. 150 It requires approximately 17 per cent more heat for flash pasteurization than for vat pasteurization.

1927 H. E. Ross Care & Handling of Milk viii. 101 Flash pasteurization is often used in pasteurizing milk and cream for manufacturing purposes where high temperatures may be used without injuring the product.

1940 Economist 28 Dec. 798/1 Ordinary pasteurisation imparts an objectionable cooked flavour... But there are certain methods such as flash pasteurisation, film evaporation and freezing which are not open to these objections.

1950 G. Porter in Proc. Royal Soc. A. 200 284 A new technique of flash photolysis and spectroscopy has been developed.

1962 R. E. Dodd Chem. Spectrosc. v. 310 An important kinetic technique which relies upon spectrophotometry is flash photolysis.

1971 G. Herzberg Spectra & Struct. Simple Free Radicals 8 (caption) Apparatus for the study of absorption spectra of free radicals in the vacuum ultraviolet by flash photolysis.

1971 Nature 1 Jan. 41/1 The technique was checked by flash photolysing a 3:1 mixture of hydrogen and nitrogen dioxide.

1971 G. Herzberg Spectra & Struct. Simple Free Radicals 13 Almost the first absorption spectrum of flash-photolyzed diazomethane showed a new transient feature..which turned out to be the spectrum of CH₂.

1874 E. H. Knight Pract. Dict. Mech. Flash-pipe, a mode of lighting gas by means of a supplementary pipe pierced with numerous small holes throughout its length.

1878 R. Hunt & F. W. Rudler Ure's Dict. Arts (ed. 7) IV. 570 The legal flash-point of petroleum.

1955 Times 26 Aug. 3/3 What actually happens is that the idealist is horrified by what he learns of police methods, his social conscience is brought to the flash-point of concentration by a love affair.

1958 Economist 13 Sept. 817/1 China's tactics seemed to be to build up heat to near flash~point and then suddenly lower the temperature.

1963 Ann. Reg. 1962 132 The flashpoint of East-West relations in 1962 was reached on 22 October.

1889 Brit. Jrnl. Photogr. 805 The characteristic of flash powder is that it contains within itself the elements by which the flash is produced.

1902 Westm. Gaz. 9 June 4/2 A considerable quantity of flash-powder wrapped up in a piece of paper.

1952 W. Granville Dict. Theatr. Terms 77 Flash powder, a chemical substance through which is passed an electric current producing a flash and a cloud of smoke. Used for explosive effects in war plays.

1966 F. H. Brightman Oxf. Bk. Flowerless Plants 56/2 The spores form a very fine, bright-yellow powder called ‘lycopodium powder’, which was formerly used as a constituent of ‘flash powder’.

1910 Ayers & Johnson in Bull. U.S. Dept. Agric. Bur. Animal Ind. cxxvi. 14 Experiments were made, using both the ‘flash’ process, which consists of heating flowing milk for from thirty to forty seconds and then cooling, and the ‘holder’ process, where the milk is heated in a tank and held for thirty minutes before cooling.

1867 W. H. Smyth & E. Belcher Sailor's Word-bk. Flash Rim, in carronades, a cup-shaped enlargement of the bore at the muzzle.

1926 D. M. Liddell Handbk. Non-ferrous Metall. II. Index 1428/2 Flash roasting.

1951 Engineering 20 July 75/2 Hydrogen sulphide in town's gas can be obtained by flash-roasting iron pyrites.

1958 A. D. Merriman Dict. Metall. 95/1 Flash roasting, a process for removing sulphur from ores by blowing the pulverised concentrates through a combustion chamber.

1952 Proc. Royal Soc. 1951–2 A. 210 440 Flash spectroscopy makes possible the recording of absorption spectra in a time less than 50 microseconds.

1953 Proc. Royal Soc. A. 216 165 The explosive oxidation of acetylene, initiated homogeneously by the flash photolysis of a small quantity of nitrogen dioxide, has been investigated by flash spectroscopy.

1898 C. A. Young Text-bk. Gen. Astron. (rev.ed.) xi. 267 The ‘flash-spectrum’..was successfully photographed at a number of stations.

1900 Proc. Royal Soc. 67 373 The centre of the flash spectrum arcs was..midway between the edges of the spectrum in the photographs obtained at mid-eclipse.

1926 H. C. Macpherson Mod. Astron. 32 Confirmatory observations of this ‘flash spectrum’, as the phenomenon of reversal from dark to bright was called, were secured at subsequent eclipses.

1950 Proc. Royal Soc. 1949–50 A. 200 299 Effect of capacity on flash spectra of krypton and hydrogen.

1922 Encycl. Brit. XXX. 253/1 Any gun which fired at night within direct view of the enemy was liable to be marked down by the ‘flash-spotting’ section... It was therefore necessary to introduce flashless powder.

1930 E. Blunden De Bello Germanico 78 I believe our observers or flash~spotters used it.

1907 Westm. Gaz. 19 Nov. 4/2 The flash steam generator, which is of the Serpollet type.

1945 G. L. Wakefield & N. W. Smith Synchronized Flashlight Photogr. ix. 109 The light-producing unit is a coiled glass tube filled with pure xenon... The flash-tube.

1946 Electronic Engin. 18 113 (title) Electronic flash tubes in high-speed photography of explosions.

1957 T. L. J. Bentley Man. Miniature Camera (ed. 5) v. 74 The practical uses of electronic flash sets are governed by the characteristics of the modern xenon-filled flash tube.

1874 E. H. Knight Pract. Dict. Mech. Flash-wheel, a water-raising wheel having arms radial or nearly so to its axle, and revolving in a chase or curved water-way by which the water passes from the lower to the higher level as the wheel rotates.

1601 Bp. W. Barlow Def. Protestants Relig. 89 The white of an egge, without salt, is flash and unsavery.

1642 J. Eaton Honey-combe Free Justific. 84 The mingling and mixing together of wine and water..maketh flash matter of both.

1612 J. Brinsley Ludus Lit. xii. 166 Matters vnfit for an Epistle, flash and to little purpose; but very childish.

1622 S. Ward Life of Faith in Death 101 Loath I am to mingle Philosophicall Cordialls with Diuine, as water with wine, least my Consolations should bee flash and dilute.

1640 T. Fuller Joseph's Coat 182 Flash in his matter, confused in his Method, dreaming in his utterance.