114 ROUGH-AND-TUMBLE ENGINEERING 



fact ought to encourage you who have two arms to 

 handle your engine to perfect ion. 



The double or two cylinder engine is becoming 

 more general and while I have been careful not to 

 recommend or condemn any particular type of engine, 

 1 will say that a naturally awkward engineer can make 

 a much more respectable showing with the double en- 

 gine, but the expert or clever engineer can show his 

 ability and skill to much better advantage with the 

 single engine. 



Now you will find somewhere in this book that I 



make use of these words: "A good horse power 



engine, or a horse power engine in good condi- 

 tion" will do certain work. 



Now what is meant by an engine in good condi- 

 tion? 



In the first place an engine to be in good condition 

 must have a clean boiler. The valve must be set, so 

 as to admit an equal amount of steam at either end of 

 the cylinder. It must not blow over, I mean by this 

 that the valve and seat must present a perfect steam 

 fitting surface otherwise the steam will "blow over" 

 or pass between the valve and seat, escaping through 

 the exhaust and your boiler will require too much wa- 

 ter and fuel. 



The rings must fit snug and close, to prevent "blow- 



