GAS AND OIL ENGINES 



free by the explosion of gunpowder, their experiments 

 being conducted about the years 1678 to 1689. Their 

 results, however, were not such as to give them other 

 than an historical interest. About a century later, in 

 1794, the Englishman Robert Street suggested the use of 

 inflammable gases as explosives, and ever since that time 

 there have been occasional experimenters along that 

 line. In 1823 Samuel Brown introduced a vacuum 

 gas engine for raising water by atmospheric pressure. 

 The first fairly practical gas engine, however, was that 

 introduced by J. J. E. Lenoir, who in 1850 proposed an 

 engine working with a cycle resembling that of a steam 

 engine. His engine patented in 1860 proved to be a 

 fairly successful apparatus. This engine of Lenoir 

 prepared the way for gas engines that have since be- 

 come so enormously important. Its method of action is 

 this: 



"To start the engine, the fly-wheel is pulled round, 

 thus moving the piston, which draws into the cylinder a 

 mixture of gas and air through about half its stroke; the 

 mixture is then exploded by an electric spark, and pro- 

 pels the piston to the end of its stroke, the pressure 

 meanwhile falling, by cooling and expansion, to that of 

 the atmosphere when exhaust takes place. In the re- 

 turn stroke the process is repeated, the action of the en- 

 gine resembling that of the double-acting steam engine, 

 and having a one-stroke cycle. The cylinder and 

 covers are cooled by circulating water. The firing 

 electricity was supplied by two Bunsen batteries and an 

 induction coil, the circuit being completed at the right 

 intervals by contact pieces on an insulating disc on the 



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