488 



THE POPULAR SCIENCE MONTHLY. 



stopping, no attention whatever being given to it in that time. It is 

 said to have gone quite largely into use in France, but it has not yet 

 made its appearance in the American market. 



In the engine as shown in the .engraving, the cylinder is placed up- 

 right, and it and the base-plate are cast in one piece. A number of 



ribs upon the former increase the radiating surface to such an extent 

 that a watei'-jacket is unnecessary. The motor can therefore be read- 

 ily moved from one place to another, an advantage of considerable 

 value in the uses for which it is intended. The mixture of gas and 

 air is admitted and discharged at the lower end of the cylinder through 

 an opening, alternately placed in communication with the gas-supply 

 and exhaust by a sliding valve. The firing of the gaseous charge is 

 done by means of two gas-jets, shown on the right side of the engine. 

 The lower one remains permanently lit, and serves to relight the upper 

 one, which is extinguished at each ignition in the cylinder. This latter 

 is placed directly opposite a small opening in the cylinder at about 



