place all the boilers on one floor
level. The economizers were placed above the boilers, instead of
behind them, which made a material saving in the width of the boiler
room. This saving permitted the setting aside of the aforementioned
gallery at the side of the operating room, closed off from both boiler
and engine rooms, for the reception of the main-pipe systems and for a
pumping equipment below it.

The advantages of the plan can be enumerated briefly as follows: The
main engines, combined with their alternators, lie in a single row
along the center line of the operating room with the steam or
operating end of each engine facing the boiler house and the opposite
end toward the electrical switching and controlling apparatus arranged
along the outside wall. Within the area between the boiler house and
operating room there is placed, for each engine, its respective
complement of pumping apparatus, all controlled by and under the
operating jurisdiction of the engineer for that engine. Each engineer
has thus full control of the pumping machinery required for his unit.
Symmetrically arranged with respect to the center line of each engine
are the six boilers in the boiler room, and the piping from these six
boilers forms a short connection between the nozzles on the boilers
and the throttles on the engine. The arrangement of piping is alike
for each engine, which results in a piping system of maximum
simplicity that can be controlled, in the event of difficulty, with a
degree of certainty not possible with a more complicated system. The
main parts of the steam-pipe system can be controlled from outside
this area.

The single tier of boilers makes it possible to secure a high and well
ventilated boiler room with ventilation into a story constructed above
it, aside from that afforded by the windows themselves. The boiler
room will therefore be cool in warm weather and light, and all
difficulties from escaping steam will be minimized. In this respect
the boiler room will be superior to corresponding rooms in plants of
older construction, where they are low, dark, and often very hot
during the summer season. The placing of the economizers, with their
auxiliary smoke flue connections, in the economizer room, all
symmetrically arranged with respect to each chimney, removes from the
boiler room an element of disturbance and makes it possible to pass
directly from the boiler house to the operating room at convenient
points alo