ENGINE No. 12, 



Simple Condensing Engine. 



Kind of engine Four valve (Corliss) 



Number of cylinders 1 



Diameter of cylinder 24i in. 



Diameter of piston rod 3i in. 



Stroke of piston 4 ft. 



Clearance 3 



H. P. constant for one Ib. m. e. p. one revolution per min. .112 H.P. 



Inside diameter of steam pipe . . 6 in. 



Inside diameter of exhaust pipe 7 in. 



Condition of valves and piston regarding leakage . . . Considerable leakage 



Data and Results of Feed- Water Test. 



Character of s+eam ( >nlinary 



Duration 5.07 Ins. 



Weight of feed-water consumed 30,920 Ibs. 



Feed-water consumed per hour (j, <>'.>'. Ibs. 



Pressure in steam pipe above atmosphere 70.2 Ibs. 



Vacuum in condenser 21 in. 



Mean effective pressure 33.06 Ibs. 



Revolutions per minute 70.2 



Indicated horse-power 258.2 I. H.P. 



Feed-water consumed per I. H. P. per hour 23.62 Ibs. 



Measurements based on Sample Diagrams. 



Initial pressure above atmosphere 63.6 Ibs. 



Cut-off pressure above zero 56.1 Ibs. 



Release pressure above zero 17.8 Ibs- 



Mean effective pressure 33.31 Ibs. 



Back pressure at mid stroke, below atmosphere 8.5 Ibs. 



Proportion of stroke completed at cut-off -J ( . 



Steam accounted for at cut-off 16.99 Ibs. 



Steam accounted for at release 17.75 Ibs. 



Proportion accounted fcr at cut-off 719 



Proportion accounted for at release .751 



Engine No. 12 exhausts into a jet condenser having a 

 direct connected air-pump. The joints about the air-pump were 

 out of repair, and the condenser was rendered somewhat ineffi- 

 cient. Steam is supplied from vertical boilers, which do not 

 superheat, but which appeared to furnish steam in a commer- 



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