ENGINE No. 93. 



This diagram is from a 7" pipe supplying a Corliss con- 

 densing engine, 32" x 54", making 47 revolutions per minute. 

 The engine diagram given is from the crank end of the 

 cylinder, and the steam-pipe diagram refers to one stroke of 

 the piston, that is, the one made from the crank end to the 

 front end. This engine was one cylinder of a pair, and the 

 steam pipe consisted of a 10" main leading from the boilers 

 and a 7" branch to each cylinder. The distance from the 

 10" to the throttle valve was 20 feet, and it contained two 

 right-angle elbows. The other cylinder was in operation when 

 the diagram was being taken. 



80^ 



60- 



40- 



20- 



o- 



10- 



On the steam-pipe diagram it appears that the pressure rises 

 just before the beginning of the stroke, and immediately after 

 it drops back to nearly the same point, and remains nearly con- 

 stant until the steam is cut off from the cylinder, when it 

 rises. Just before the middle of the stroke the pressure falls 

 again, this action being due presumably to the other cylinder 

 taking steam, followed by another rise in the pressure at about 

 the time of the cut-off in the other cylinder. Just prior to 

 the beginning of the return stroke the pressure rises as before, 

 and again drops soon after the beginning of the return stroke, 

 when the other end of the cylinder begins to take steam. 



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