Page:Reflections on the Motive Power of Heat.djvu/123

that which will be required to raise 1 kilogram of air 1 degree would have for its value 0.267. Thus the quantity of heat furnished by the body A is

   0.267 units.

This is the heat capable of producing 0.000000372 units of motive power by its fall from 0°.001 to zero.

For a fall a thousand times greater, for a fall of one degree, the motive power will be very nearly a thousand times the former, or

   0.000372.

If, now, instead of 0.267 units of heat we employ 1000 units, the motive power produced will be expressed by the proportion

   ${\tfrac {0.267}{0.000372}}$ = ${\tfrac {1000}{x}}$, whence x = ${\tfrac {372}{267}}$ = 1.395.

Thus 1000 units of heat passing from a body maintained at the temperature of 1 degree to another body maintained at zero would produce, in acting upon the air,

   1.395 units of motive power.

We will now compare this result with that furnished by the action of heat on the vapor of water.