144 ENGINE TESTS. 



Engine No. 35 is a horizontal cross-compound unjacketed 

 engine, provided with a shaft governor operating on the cut-off 

 of the high-pressure cylinder. The valves are of the piston 

 type without packing. A jet condenser is used operated by an 

 independent air-pump driven with steam taken from the engine 

 pipe. The quantity thus used, as also that consumed by the 

 boiler feed-pump, was determined by independent tests and 

 allowed for. Steam is supplied from vertical water-tube boil- 

 ers, and a separator placed in the steam pipe secured what was 

 believed to be commercially dry steam. The steam showed no 

 superheating. The valve in each cylinder was found to leak 

 badly. The piston of the high-pressure cylinder was fairly 

 tight. Owing to the leakage of the low-pressure valve no 

 leakage observations could be made upon the low-pressure 

 piston. The load consisted of dynamos furnishing current for 

 electric lighting. 



There is a close agreement between the steam accounted for 

 by the indicator in the two cylinders, which might be surprising 

 in view of the fact that the cylinders are unjacketed, were it 

 not known that the steam valve of the high-pressure cylinder 

 showed considerable leakage. Some of the steam shown on 

 the low-pressure diagram was undoubtedly due to this cause. 



