97 



ENGINES. 



It is also economy to have the engine at least 25 per cent, 

 larger than actually needed. In choosing, simplicity, durability 

 and steadiness should be considered, and a good governor is very 

 important. Again I quote Mr. Krebs, who recommends one made 

 by the Straight Line Engine Co., Syracuse, N. Y., (Fig. 86) : 



"The piston in an engine should be an easy fit, so as to move 

 with little friction, and at the same time it should be steam tight. 



"If the back cylinder cover is removed, little steam should 

 escape if you place the engine on the front center, at which point 

 the valve ought to admit steam to that end. Again place the en- 

 gine on three-fourth stroke and turn on steam ; here the slide valve 

 ought to close both ports, and if the valve is tight no steam will 

 escape into the cylinder or from the exhaust pipe. Should steam 

 escape in quantities your engine needs repairs, in which case you 

 will have to get a trained mechanic to face and bed your slide 

 valve or refit the piston, as untrained people generally make bad 

 worse. 



"The escape of steam in the positions mentioned might also 

 be caused by the eccentric working loose or having shifted. The 

 angle of advance of the eccentric for ordinary slide valves should 

 be such as to open the steam-port when the piston is at the end 

 of the stroke, and the length of the valve-rod should be adjusted 

 to give the valve equal opening at both ends." 



Oil sufficiently, but do not slop it on the floor. Wipe the 

 engine when stopping for the day and keep it bright and clean. 

 Take a pride in it ! 



Before starting see that the governor is in good order, the 

 belt not too tight nor too slack, that the engine is level and firmly 

 bolted and that all boxes and shafting as well as pins and screws 

 are snug and tight, that the exhaust is open and the crank not on 

 the dead center and turn on steam slowly. Watch bearings closely 

 in the beginning, and if a hot-box should develop and plenty of 

 oil does not relieve it, stop and loosen it a little and try to finish 

 your work. You may have to stop long enough to cool and polish 

 before starting. If there is a grease cup on the crank and it is 

 kept filled, it will seldom heat. A little plumbago added to the 

 oil is also claimed to be a good thing for a hot-box. 



Knocking or hammering may also be due to the piston 

 touching the heads, to the fly-wheel being loose, to loose keys or 

 slack nuts. Worn bearings may be filed on the edges so as to fit. 



