Handbook of Railroad Construction; For the use of American engineers. / Containing the necessary rules, tables, and formulæ for the location, construction, equipment, and management of railroads, as built in the United States.

by George L. Vose

First, Cubic feet of water per hour
16 = grate area in square ft.

Second, S = √ac × 21.2 = heating surface,

where a is the grate area, and c the hourly consumption of water in cubic feet.

From the same formula,

Grate area, or

a = (S/21.2)²
c

Also water consumption, or

c = (S/21.2)²
a

(See table 9.)

No. 10.