emarkable in this respect, that the quantity
of air admitted to the fuel, the loss by convection and
radiation, and the composition of the smoke were determined. The
facts observed were as follows:

Steam pressure 53 lb................................... = 300.6 deg. F.
lb.
Fuel--Water in coke and wood........................... 26.08
Ash.............................................. 10.53
Hydrogen, oxygen, nitrogen, and sulphur.......... 7.18
------
Total non-combustible..................... 43.79
Carbon, being useful combustible................. 194.46
------
Total fuel................................ 238.25

Air per pound of carbon................................ 17-1/8 lb.
Time of experiment..................................... 4 h. 12 min.
Water evaporated from 60 deg. into steam at 53 lb. pressure 1,620 lb.
Heat lost by radiation and convection.................. 70,430 units.
Mean temperature of chimney............................ 700 deg. F.
" " " air................................ 70 deg. F.

No combustible gas was found in the chimney.

I will apply Carnot's doctrine to this case.

Potential energy of the fuel with respect to absolute zero:
Units.
239.25 lb. x 530 deg. abs. x 0.238 ...................... = 30,053
194.46 lb. x 17-1/8 x 530 deg. x 0.238,
the weight and heat of air....................... 420,660
194.46 x 14,544 units heat of combustion of carbon... 2,828,200
---------
Total energy 3,278,813
Heat absorbed in evaporating 26.08 lb. of water
in fuel............................................ -29,888
---------
Available energy.......................... 3,248,425

Temperature of furnace--

The whole of the fuel was heated up, but the heat absorbed in the
evaporation of the water lowered the temperature of the furnace,
and must be deducted from the heat of combustion.