case one common flue carries the gases into the side of the chimney.
The two common flues last mentioned enter at opposite sides of the
chimney. The main flues are arranged and fitted with dampers, so that
the gases can pass directly to the chimney, or else they can be
diverted through the economizers and thence reach the chimney.

The uptakes from each boiler are constructed of 3/8-inch plate and
each is lined with radial hollow brick 4 inches thick. Each is
provided with a damper which operates on a shaft turning in roller
bearings. The uptakes rest on iron beams at the bottom, and at the
top, where they join the main flue, means are provided to take up
expansion and contraction.

The main flue, which rests on the economizer floor, is what might be
called a steel box, constructed of 3/8-inch plate, 6 feet 4 inches
wide and 13 feet high. The bottom is lined with brick laid flat and
the sides with brick walls 8 inches thick, and the top is formed of
brick arches sprung between.

[Sidenote: _Steam Piping_]

The sectional plan adopted for the power house has made a uniform and
simple arrangement of steam piping possible, with the piping for each
section, except that of the turbine bay, identical with that for every
other section. Starting with the six boilers for one main engine, the
steam piping may be described as follows: A cross-over pipe is erected
on each boiler, by means of which and a combination of valves and
fittings the steam may be passed through the superheater. In the
delivery from each boiler there is a quick-closing 9-inch valve, which
can be closed from the boiler room floor by hand or from a distant