Construction of the Gasoline Engine. 525 



horizontal type. These two types of engines are repre- 

 sented in Figs. 255 and 256. 



CONSTRUCTION OF THE GASOLINE ENGINE. 



659. Cylinder. The cylinder of the ordinary gasoline 

 engine with its piston is not widely different from that of 

 the steam engine, except that here there is nothing which 

 corresponds to the steam chest and the slide valve, and the 

 cylinder has a double jacket through which water is kept 

 circulating to prevent over-heating. In Fig. 255 A repre- 

 sents the cylinder and the opening on the side is the ex- 

 haust port. 



The piston has essentially the same construction as that 

 of the steam engine represented in Fig. 251, using similar 

 elastic metallic packing rings. There being no head in one 

 end of the cylinder the piston can usually be seen. 



660. Pumping Mechanism. Formally it was the practice 

 to arrange the gasoline supply tank so that the oil would 

 flow by gravity to the engine, but this practical experience 

 has proved to be unsafe on account of the tendency for 

 leaks to develop and flood the engine room with the explo- 

 sive oil. The plan now generally followed is to use an 

 automatic pump, represented in connection with the en- 

 gine in Fig. 257, where D is the plunger and A, B, C parts 

 for working it when it is desired to throw a charge into the 

 reservoir II. The gasoline comes from a tank outside the 

 building through the valve F, and is discharged from the 

 pump th rough the pipe E into H. 



The disk with the hand wheel J is used to regulate the 

 amount of oil going to the engine and when the pointer I 

 is over the letter O the valve is wide open, but the proper 

 amount of oil is supplied when the pointer is at R in this 

 onaine. The air is drawn in through the same chamber 

 If by means of a pipe not shown in the cut, which ends un- 

 der the base of the engine where as little dust as possible 

 will be sucked in. 



