104 



ENGINE TESTS. 



for this. At a point between the trap and the engine the steam 

 was found by calorimeter test to contain 2-J- per cent of mois- 

 ture. The exhaust valves were practically tight. The steam 

 valves and pistons showed some leakage. The engine worked 

 in connection with a water-wheel driving cotton machinery. 



In examining the results of this test, which in view of the 

 long distance which the steam had to travel between the boil- 

 ers and the engine, shows excellent economy, the part which 

 the vacuum played cannot be overlooked. This was phenomi- 

 nally low, the back pressure at the middle of the stroke being 

 only about one pound above a perfect vacuum. 



ENGINE No. 22 



Head End 



Crank End 



80 



60 



-40 



-20 



- 



-10 

 r80 



60 

 -40 

 -20 



- O 



-10 



