GATINEAU 270 GAUGE, PRESSURE force imprisoned in the 400 pounds of wet guncotton. See Ordnance. GATINEAU (ga-ti-no'), a river of Canada, Quebec Province, the largest affluent of the Ottawa, rising in some lakes, and flowing almost due S. to enter the Ottawa nearly opposite Ottawa City. It is not navigable more than 5 miles above the Ottawa except by canoes, but its rapid waters are well stocked with fish and available as water powers. GATLING, RICHARD JORDAN, an American inventor; born in Hertford co., N. C, Sept. 12, 1818. While a boy he assisted his father in perfecting a machine for sowing cotton seed, and an- other for thinning out cotton plants. Subsequently he invented a machine for sowing rice. Removing to St. Louis, in 1844, he adapted this invention to sow- ing wheat in drills. For several winters he attended medical lectures in Cincin- nati, and in 1849 removed to Indian- apolis, where he engaged in railroad en- terprises and real estate speculations. In 1850 he invented a double-acting hemp brake, and in 1857 a steam plow, which, however, he did not bring to any practical result. In 1861 he conceived the idea of the revolving battei'y gun which bears his name. Of these he con- structed six at Cincinnati, which were destroyed by the burning of his factory. Afterward he had 12 manufactured else- where, which were used by General Butler on the James river. In 1865 he improved his invention, and in the year following, after satisfactory trial, it was adopted into the United States service. It has also been adopted by several European governments. Died Feb. 23, 1903. GATLING GUN, a machine gun, in- vented by Richard J. Catling. The gun consists of a series of barrels in com- bination with a grooved carrier and lock cylinder. The main features of the gun are: (1) Each barrel in the gun is provided with its own independent lock or firing mechanism. (2) All the locks revolve simultaneously with the barrels, carrier and inner breech, when the gun is in operation. The locks also have a reciprocating motion when the gun is rotated. The gun cannot be fired when either the barrels or locks are at rest. GATSHINA, a town of Russia, 30 miles S. S. W. of Petrograd. It has some manufactures of porcelain, and several barracks, but is especially worthy of mention for its royal palace, surrounded by one of the finest pleasure gardens in Europe, which were the favorite summer seat of the Emperor Paul I., and the winter residence — practically, owing to precautions against Nihilists, the prison — of Alexander III. GATTI-CASAZZA, GIULIO, an Italian operatic manager, born in Udine, Italy, in 1869. He graduated as a naval engi- neer at the Polytechnic College of Genoa. From 1892 to 1898 he was director of the Municipal Theater at Ferrara, and from 1898 to 1908 was director of the Teatro Alia Scala in Milan. In the same year he was appointed director of the Metropolitan Opera House. In 1910 he married Frances Alda, an operatic so- prano. GAUCHO (gou'cho), a native of th© pampas of La Plata, and of Spanish de- scent. The Gauchos live by cattle-breed- ing, and are noted for their skill in horse- manship and the use of the lasso and the bolas. GAUGE, a standard of measurement. As applied to railways, gauge signifies the distance between the centers of each pair of rails, which in the ordinary or narrow gauge is 4 feet 8% inches. The broad gauge of the Great Western Rail- way of England was formerly 7 feet; the Irish, Indian, and Spanish gauge is 5 feet 6 inches. Special narrow gauges have recently been adopted for mountain and mineral lines, such as the 3 feet 6 inch gauge of the Norwegian lines. Gauge is also the name applied to vari- ous contrivances for measuring any spe- cial dimension, such as the wire gauge, an oblong plate of steel, with notches of different widths cut on the edge, and numbered, the size of the wire being de- termined by trying it in the diff^erent notches till one is found which it exactly fits. The thickness of sheet metal is tried by a similar gauge. GAUGE, PRESSURE, an instrument for indicating the intensity of a fluid contained in a closed vessel. Gauges are divided into three classes: the mercurial pressure gauge, the air manometer, and the spring gauge. The mercurial gauge consists of an inverted siphon or "U" tube of glass, the lower part of which contains mercury, and whose vertical legs are divided either in parts of an inch or divisions indicating pounds per square inch. One leg of the tube is open to the atmosphere and the other com- municates with the vessel containing the fluid. The difference in level of the mer- cury indicates the difference in pressure between the atmosphere and the fluid. The air manometer consists of a long vertical glass tube closed at the upper end, open at the lower end, containing air and immersed in a transparent liquid
