GAS ENGINE 



2403 



GAS ENGINE 



which means to brag or bluster. Dumas gives 

 an admirable example of the popular concep- 



FRANCE 



S P A'V.I N Dragon 



GASCONY 



tion of a Gascon in D'Artagnan, the hero of 

 The Three Musketeers. 



GAS ENGINE, an engine in which the mo- 

 tive power is produced by the explosion or 

 combustion of gas in a closed cylinder. It is 

 also called an internal-combustion engine. 

 Such engines have reached a high degree of de- 

 velopment in recent years, and are used for a 

 variety of purposes. They drive automobiles, 

 motorcycles and motor boats; they are used in 

 factories of many kinds, and they furnish 

 power for churns, plows, tractors and all sorts 

 of machinery on the farm. Their compara- 

 tively light weight and small bulk make them 

 superior to the steam engine for many pur- 

 poses. A small gas engine, moreover, is prac- 



and the most satisfactory power-producer if 

 only a small horse power is required. For 

 large power plants other forms of power-pro- 

 ducers may be equally or more satisfactory; 

 this fact depends on local conditions. 



Kind of Fuel. The gas used may be natural 

 gas, coal gas, producer gas, or a vapor pro- 

 duced from gasoline or any other petroleum 

 product. Engines in which gasoline is used 

 and these are by far the commonest variety 

 are usually called gasoline engines. They dif- 

 fer from ordinary gas engines only in that the 

 fuel must first be vaporized by means of a 

 carburetor (which see). In stationary engines 

 either liquid or gas may be used as fuel. In 

 . portable engines, such as those used in auto- 

 mobiles and motor boats, the liquid fuels are 

 better, for they are usually cheaper, easier to 

 handle and easier to obtain than compressed 

 gases in storage tanks. 



The Principles of Operation. A gas engine 

 is an internal-combustion engine, that is, the 

 combustion occurs inside the cylinder. The 

 first requirement of such an engine is an en- 

 closed space, in which combustion of the gas 

 and the resulting increase of pressure may 



PRINCIPAL PARTS OF THE GAS ENGINE 



(a) Cylinder; (b) piston; (c) connecting rod; (d) flywheel; (e) oil cup; 

 (/) cooling water outlet; (fir) ventilator; (ft) air inlet; (j) exhaust. 



tically as efficient as a large one, whereas a 

 small steam engine is much less efficient than 

 a large one. A gas engine is easily operated, 

 and is instantly ready for use. For these rea- 

 sons a small gas engine is the most economical 



take place. This enclosed space, or combus- 

 tion chamber, is the cylinder. One wall of this 

 air-tight, gas-tight chamber must be adjustable, 

 in such a way that the pressure from combus- 

 tion may be used to perform work. This is 



