EFFECTIVE PRESSURE OF STEAM ON PISTON.
With different rates of expansion,
boiler pressure being assumed as 100 lbs. per square inch.
| Steam cut off at | ¾ | of stroke | = 90 | lbs. | effective pressure. |
| “““ | ⅔ | ““ | = 80 | “ | ““ |
| “““ | ½ | ““ | = 69 | “ | ““ |
| “““ | ⅓ | ““ | = 50 | “ | ““ |
| “““ | ¼ | ““ | = 40 | “ | ““ |