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gas mask

(Encyclopedia)gas mask, face covering or device used to protect the wearer from injurious gases and other noxious materials by filtering and purifying inhaled air. In addition to military use (see chemical warfare)...

Battle of Britain

(Encyclopedia)Battle of Britain, in World War II, series of air battles between Great Britain and Germany, fought over Britain from Aug. to Oct., 1940. As a prelude to a planned invasion of England, the German Luft...

cotton gin

(Encyclopedia)cotton gin, machine for separating cotton fibers from the seeds. The charkha, used in India from antiquity, consists of two revolving wooden rollers through which the fibers are drawn, leaving the see...

Trippe, Juan Terry

(Encyclopedia)Trippe, Juan Terry trĭp [key], 1899–1981, pioneering American aviation executive, b. Sea Bright, N.J. A U.S. Navy pilot (1917–18), he graduated (1921) from Yale, and worked briefly on Wall Street...

mirage

(Encyclopedia)mirage mĭräzhˈ [key], atmospheric optical illusion in which an observer sees in the distance a nonexistent body of water or an image, sometimes distorted, of some object or of a complete scene. Exa...

internal-combustion engine

(Encyclopedia)CE5 Internal-combustion engines: In the four-stroke reciprocating engine (above), a mixture of fuel and air is taken into the chamber on the down-stroke of the piston, is compressed on the up-strok...

Clovis

(Encyclopedia)Clovis. 1 City (2020 pop. 120,124, Fresno co., S central Calif., near the foothills of the Sierra Nevada range; inc. 1912. It is a growing trade ...

cloud chamber

(Encyclopedia)cloud chamber, device used to detect elementary particles and other ionizing radiation. A cloud chamber consists essentially of a closed container filled with a supersaturated vapor, e.g., water in ai...

argon

(Encyclopedia)argon ärˈgŏn [key] [Gr.,=inert], gaseous chemical element; symbol Ar; at. no. 18; at. wt. 39.948; m.p. −189.2℃; b.p. −185.7℃; density 1.784 grams per liter at STP; valence 0. Argon is a col...

caisson

(Encyclopedia)caisson kāˈsən, –sŏn [key] [Fr.,=big box], in engineering, a chamber, usually of steel but sometimes of wood or reinforced concrete, used in the construction of foundations or piers in or near a...