locomotive consists of two units, each of which has four driving
wheels, and carries its own motor and battery. The use of two units
allows the locomotive to round curves with very small overhangs, as
compared with a single-body locomotive. Curves of 12 feet radius can
be turned with ease. The gross weight of the locomotive is about five
tons, all of which is available for traction.

[Sidenote: _Coal
Downtakes_]

The coal from the coal bunkers is allowed to flow down into the boiler
room through two rows of downtakes, one on each side of the central
gangway or firing place. Each bunker has eight cast-iron outlets, four
on each side, and to these outlets are bolted gate valves for shutting
off the coal from the corresponding downtakes. From these gates the
downtakes lead to hoppers which are on the economizer floor, and from
these hoppers the lower sets of downtakes extend down to the boilers.

Just above the hoppers on the economizer floor the coal downtakes are
provided with valves and chutes to feed the coal, either into the
hopper or into the distributing flight conveyor alongside of it. These
distributing conveyors, one corresponding with each row of downtakes,
permits the feeding of coal from any bunker or bunkers to all the
boilers when desired. They are the ordinary type of flight conveyor,
capable of running in either direction and provided with gates in the
bottom of the trough for feeding into the several above mentioned
hoppers. In order to eliminate the stresses that would develop in a
conveyor of the full length of the building, the conveyors are of half
the entire length, with electric driving engines in the center of each
continuous line. The installation of this conveyor system, in