per cent of moisture in coal,
t = the temperature of air in the boiler room,
T = temperature of the flue gases,
.47 = the specific heat of superheated steam at the atmospheric
pressure and at the flue gas temperature,
(212-t) = B. t. u. necessary to heat one pound of water from the
temperature of the boiler room to 212 degrees,
970.4 = B. t. u. necessary to evaporate one pound of water at 212
degrees to steam at atmospheric pressure,
.47(T-212) = B. t. u. necessary to superheat one pound of steam at
atmospheric pressure from 212 degrees to temperature T.

[Illustration: Portion of 15,000 Horse-power Installation of Babcock &
Wilcox Boilers, Equipped with Babcock & Wilcox Chain Grate Stokers at
the Northumberland, Pa., Plant of the Atlas Portland Cement Co. This
Company Operates a Total of 24,000 Horse Power of Babcock & Wilcox
Boilers in its Various Plants]

(B) Loss due to heat carried away in the steam produced by the burning
of the hydrogen component of the fuel. In burning, one pound of hydrogen
unites with 8 pounds of oxygen to form 9 pounds of steam. Following the
reasoning of item (A), therefore, this loss will be:

Loss in B. t. u. per pound = 9H((212-t)+970.4+.47(T-212)) (34)

where H = the percentage by weight of hydrogen.

This item is frequently considered as a part of the unaccounted for
loss, where an ultimate analysis of the fuel is not given.

(C) Loss due to heat carried away by dry chimney gases. This is
dependent upon the weight of gas per pound of coal which may be
determined by formula (16), page 158.

Loss in B. t. u. per pound = (T-t)x.24xW.

Where T and t have values as in (33),

.24 = specific heat of chimney gases,

W = weight of dry chimney gas per pound of coal.

(D) Loss due to incomplete combustion of the carbon content of the fuel,
that is, the burning of the carbon to CO instead of CO_{2}.

10,150 CO
Loss in B. t. u. per pound = Cx--------- (35)
CO_{2}+CO

C = per cent of carbon in coal by ultimate analysis,

CO and CO_{2} = per cent of CO and CO_{2} by volume from flue gas
analysis.

10,150 = the number of heat units generated by burning to CO_{2} one
pound of carbon contained in carbon monoxide.

(E) Loss due to unconsumed carbon in the ash (it being usually assumed
that all the combustible in the ash is carbo