ives the
condensed water. This arrangement afforded a condensing surface of about
800 square feet. It should be mentioned that with larger engines Mr.
Rowan employs as much as 1,600 feet of condensing surface. The nearness
of the chambers to each other tends no doubt to diminish the power of
condensing the steam, but this is somewhat compensated by the artificial
circulation of air produced by the movement of the carriage. But in any
case, if there is surplus steam, the pipe from the condenser causes it to
pass under the grate, whence it rises superheated and invisible through
the fire and up the chimney.

Under the carriage attached to the framing are four reservoirs, holding
about three and a half cubic feet of water, of which water space one-half
acts as a reservoir for cold feed water, and half for the condensed
water. A tube from the small reservoir on the engine communicates through
valves with the reservoirs of hot and cold water on the carriage.

The consumption of cold water measured during two days was 2.86 lb. per
kilometer; assuming that the boiler evaporated 6.5 lb. of water per pound
of coal, the cold water formed one-fifth of the total feed water
required.

The carriage, i. e., the part occupied by passengers, is 21 ft. 8 in. in
length. It holds seats for forty-five passengers, besides those who would
stand on the gangway and platform. The seats are placed transversely on
each side of a central corridor, each seat holding two people. The
platform of the carriage is about 2 ft. 6 in. above the rails. Passengers
have access to the interior from behind by means of the end platform, and
in front near the engine from the two sides. As already mentioned, the
hind part of the carriage rests upon two wheels, the front part being, as
already mentioned, supported on the engine bogie. To effect this support,
the hinder part of the framing of the engine is formed in a half circle,
with a broad groove, in which the ends of two springs are arranged to
slide. The centers of the springs form the support of the framing of the
carriage.

The framing of the engine bogie is attached to the hind bogie truck of
the carriage by two diagonal drawbars. The coupling is effected by bolts
close to the engine, and the car is drawn entirely by means of the bogie
pin of the hind bogie. The trucks are 16.5 ft. apart.

Table I. above shows the dimensions of different parts of these three
steam motors, as well as their weights.

Th