in diameter and a wheel base of 15 ft. 9 in. The frames are single,
with inside bearings to all the wheels; the cylinders are inside, 17 in.
diameter and 24 in. stroke. The boiler is 10 ft. 2 in. long and 4 ft. 3
in. diameter; the fire-box is of copper with a fire-grate area of 17.8
square feet, and the heating surface is in the tubes 1,080 square feet,
fire-box 102 square feet; total, 1182 square feet. The weight in working
order is about 35 tons. These engines have a tractive power of 89 lb. per
pound of mean steam pressure in the cylinders, and their consumption of
coal with trains averaging nine coaches is about 20 lb. per mile. The next
type of engine designed has coupled wheels under the barrel of the boiler
6 ft. 6 in. diameter, with cylinders 171/4 in. diameter and 26 in. stroke,
and were found so successful that Mr. Stroudley designed a more powerful
engine of the same class, especially to take the heaviest fast trains in
all weathers.

The 8:45 A.M. train from Brighton has grown to be one of the heaviest fast
trains in the kingdom, although the distance it runs is but very short,
while it is also exceptional in consisting entirely of first class
coaches, and the passengers mainly season ticket holders; it often weighs
in the gross 350 tons, and to take this weight at a mean speed of
forty-five to fifty miles an hour over gradients of 1 in 264 is no light
work.

[Illustration: FIG. 6.--LONDON, BRIGHTON, AND SOUTH COAST RAILWAY.]

The engines known as the "Gladstone" type have inside cylinders 181/4 in.
diameter and 26 in. stroke, with coupled wheels 6 ft. 6 in. diameter under
the barrel of the boiler; the trailing wheels are 4 ft. 6 in. diameter,
and the total wheel base is 15 ft. 7 in. The frames are inside, of steel 1
in. thick, with inside bearings to all the axles. The cylinders are cast
in one piece 2 ft. 1 in. apart, but in order to get them so close together
the valves are placed below the cylinders, the leading axle coming between
the piston and slide valve. The boiler is of iron, 10 ft. 2 in. long, and
4 ft. 6 in. diameter; and the heating surface is, in the tubes, 1,373
square feet; fire-box, 112 square feet; total, 1,485 square feet. The
grate area is 20.65 square feet, and the tractive power per pound of mean
cylinder pressure is 111 lb. The weight in full working order is--leading
wheels, 13 tons 16 cwt.; driving wheels, 14 tons 10 cwt.; trailing wheels,
10 tons 8 cwt.; total, 38 tons 14 cwt. The