ENGINE No. 7O. 



Four valve, 18" x 42". Speed, 55 revolutions per minute. 



In this engine the steam valves are double poppet, and the 

 exhaust valves, slides. The mechanism is driven by means of 

 bevel gears. The adjustment of the valves consisted in moving 

 the driving-gear forward on the shaft two teeth. The total 

 number of teeth on this gear was 44. The diagrams are from 

 the head end, No. 70a being taken before, and No. 706 after, 

 the changes. 



ENGINE No. 7Oa 



ENGINE No. 7Ob 



201 



