In order to burn the finer grades of anthracite coal in sufficient
quantities to obtain boiler rating with the hand-fired grates, and in
order to secure a large excess over boiler rating with other coals, a
system of blowers and air ducts has been provided in the basement
under the boilers. One blower is selected for every three boilers,
with arrangements for supplying all six boilers from one blower.

The blowers are 11 feet high above the floor and 5 feet 6 inches wide
at the floor line. Each blower is direct-connected to a two crank
7-1/2 x 13 x 6-1/2-inch upright, automatic, compound, steam engine of
the self-enclosed type, and is to provide a sufficient amount of air
to burn 10,000 pounds of combustible per hour with 2 inches of water
pressure in the ash pits.

[Sidenote: _Smoke Flues
and
Economizers_]

The smoke flue and economizer construction throughout the building is
of uniform design, or, in other words, the smoke flue and economizer
system for one chimney is identical with that for every other chimney.
In each case, the system is symmetrically arranged about its
respective chimney, as can be seen by reference to the plans.

The twelve boilers for each chimney are each provided with two round
smoke uptakes, which carry the products of combustion upward to the
main smoke flue system on the economizer floor. A main smoke flue is
provided for each group of three boilers, and each pair of main smoke
flues join together on the center line of the chimney, where in each