NOTES ON STATIONARY ENGINES. 



45 



Rkplies. 

 Tho troubles referred to in connection with pump valves 

 appear to liavo been misunderstood. Tor this defect of 

 clearness an apology must bo entered. The occasional 

 noise in the absence of air was referred to, but the real 

 trouble i.s that with, objectionable air spaces the pumps will 

 not draw at all ; on long lifts and with warm water this is 

 an uncomfortable fact which will bring itself home. There 

 is not the least objection to the presence of air, but a gi'cat 

 one to its accumulation. 



100 



2()0 



CO 



100 2eo 



100 



80 



60 



60 



A 



) 200 



< i 



60 



100 



100 



100 



r 



A 





83 J 



i 



A 



mi 100 



^ 



I ^ 



]00 40 



The diagrams show that the correct balance in a com- 

 pounded beam engine, when the work done is equally divided 

 between the two cylinders, is attained by placing the high- 

 pressure cylinder at one-third of the distance from the 

 main centre to the connecting rod centre, neglecting the 

 weight of the beam, etc. 



