GAS ENGINE 267 GAS, NATURAL similar gas flames exist in the sun, and are one main source of its light and heat GAS ENGINE, an engine in which motion is given to the piston by the com- pression and expansion or explosion of a mixture of a combustible gas and air. The first effective gas engine was brought into public use by M. Lenoir in 1860. In the Otto engine the cylinder is generally horizontal and single-acting, with a trunk piston, and it takes two revolutions of the crank shaft to com- plete a cycle of operations. During the first forward stroke gas and air are drawn in, in the proportion proper to form an explosive mixture; during the first backward stroke the mixture is compressed into a large clearance space behind the piston. When the next for- ward stroke is about to begin, the com- pressed mixture is ignited, and work is done by the heated gases during the second forward stroke. The second back- FLY BALC Governor CYLINDER / WIPCROIL INLET / ^ without regard to its illuminating pur- poses. Various forms have been con- trived. Also a furnace of which the fuel is gas from burners suitably disposed in the chamber for the purpose required. Steam boilers and metallurgic furnaces are sometimes heated in this manner. GASKELL, MRS., an English novelist; born in Chelsea, London, England, Sept. 29, 1810. Her maiden name was Eliza- beth Cleghorn Stevenson, and her father was in succession teacher, preacher, farmer, boarding-house keeper, writer, and Keeper of the Records to the Treas- ury. She was brought up by an aunt at Knutsford — the Cranford of her story, and was carefully educated. She mar- ried in 1832 William Gaskell (1805- 1884), a Unitarian minister in Manches- ter. In 1848 she published anonymously her "Mary Barton," which at once arrest- ed public attention. It was followed by "The Moorland Cottage" (1850) ; "Cran- ford" (1853); "Ruth" (1853); "Life of CRANK SHAFT GUARD OILCUPS FOR CRANKSHAFT FLY WMEEU BED M.^ HORIZONTAL OTTO GAS ENGINE (Nearer Fly-Wheel Is omitted to show detail) ward stroke completes the cycle by caus- ing the burned gases to be expelled into an exhaust pipe leading to the outer air. Since only one of the four strokes re- quired to complete a cycle is effective in doing work, a heavy flywheel is used to furnish a large magazine of energy. A centrifugal governor controls the engine by cutting off the supply of gas. An engine possessing much originality is Atkinson's. GAS FURNACE, a small furnace, much employed for laboratory purposes, and which is so arranged as to receive the maximum heating powers of the gas Charlotte Bronte" (1857); "Right at Last" (1860) ; "Sylvia's Lovers" (1863) ; and "Wives and Daughters" (1865). She died in Alton, Hampshire, England, Nov. 12, 1865. GAS METER, a machine for measur- ing the quantity of gas passing through it. Citizen Seguin described a gas meter at the sitting of the National Institute of France, Oct. 6, 1797. The wet meter was invented by Clegg in 1807, and improved by Crosley in 1815. The dry meter was invented by Malam in 1820, and improved by Defries in 1838. GAS, NATURAL. See Natural Gas,
