CHAPTER XXIII 



MOTIVE POWER 



THE choice of motive power is one which deserves careful 

 consideration. Suction-gas engines give a cheap and 

 efficient motive power; but on most estates timber for char- 

 coal is soon exhausted and coal not readily obtainable at a 

 reasonable price. 



Where cheap coal can be regularly obtained the suction-gas 

 engine can hold its own against oil-fuel engines. 



Oil fuel is abundant everywhere. Oil-engines are easily 

 managed safely and kept clean without dust or difficulty. 

 Hence they are in general favour in factories and rubber 

 plantations. Among the cheaper makes the Hornsby oil- 

 engine is one of the very best and seldom gets out of order. 

 Instead of putting down, for example, one large engine of say 

 70 h.p., it is more economical, as well as more advantageous, 

 to lay down two engines of 35 h.p. each. The additional cost 

 is but slight. The engines are lighter and more easily trans- 

 ported to the estate. Should only three or four machines be 

 running, only one engine need be in operation. If a break- 

 down occurs from any cause there is always one engine in 

 working order, and factory operations are not seriously inter- 

 rupted. The Diesel oil-engine costs considerably more than 

 most other makes, but it is exceedingly economical in its con- 

 sumption of liquid fuel, a 5o-h.p. engine being guaranteed not 

 to consume more than one half-pound of liquid fuel per horse- 

 power per hour. A 5o-h.p. engine thus runs with a full load 

 at a cost of about 25 dollar cents per hour. 



It is always most desirable to have a good margin of motive 

 power over what is thought to be essential for the driving of 

 machinery. Engines do not always develop power with full 

 efficiency. Cases have come under personal observation where 

 a 32 horse-power engine was unable to drive three mills at any- 



182 



