The weight exhausted per stroke is therefore 0.369 - 0.049 = 0.32 pound.
The number of strokes per hour is 150 2 60 = 18,000, from which the steam accounted for by the diagram is found to be 18,000 0.32 = 5760 pounds, or 5760 217 = 26.5 pounds per indicated horsepower per hour.
If the cylinder condensation for this type of engine is 20 per cent of the total steam consumption, the water rate will be 26.5 0.8 = 33.1 pounds per indicated horsepower per hour.
In the present case it has been a.s.sumed, for simplicity, that the head- and crank-end diagrams were exactly alike, except for the piston rod. Ordinarily, the above process should be carried out for both head and crank ends, and the results averaged.