Oil Engines. 



441 



tank in the engine base and forcing it through the spraying jet 

 into the vapouriser ; the rocking levers for working the valves 

 and actuated by the cams on the half-speed shaft, which also 

 works the governor ; and the vapouriser enclosed in a partly 

 removable cover. This cover and a water jacket round part of 

 the vapouriser afford further means of suiting the tempera- 

 ture of the vapouriser to the oil in use and the work being 

 done. 



The same type of engine is adapted as a portable engine for 

 farm use by mounting it and a jacket water-cooling tank on a 

 four-wheel underframe with shafts. The advantages which 

 accrue from the use of the portable oil engine are partly derived 

 from the low cost of oil fuel, namely, from about |d. to fd. per 

 horse- power hour (or less than this when Texas oil can be 



Fig. 3.— The Ruston & Proctor Small Oil Engine. 



obtained and used), partly from its being able to dispense almost 

 entirely with water supply and its labour and haulage cost, and 

 partly from the stoppage of fuel consumption with stoppage of 

 the engine. 



Another typical engine made in the fixed and the portable 

 form is the Ruston engine, in which the construction and opera- 

 tion of the vapouriser differs essentially from those of the 

 engine previously described. The general arrangement of the 

 engine may be gathered from Fig. 3, and the important 

 features of the vapouriser may be explained by reference to 

 Figs. 4 and 5. 



The engine is of the four-cycle type, the four operations in the 

 cylinder being, as already described, effected by two revolutions 

 of the crank shaft, and consisting of (1) outstroke sucking in 

 charge of air and oil vapour ; (2) instroke compressing that 



