nder after the stroke has
been performed, is projected up the chimney H. The water in the boiler of
course covers the tubes and also the top of the furnace or fire box. It
will be understood that there are two engines in each locomotive, though,
from the figure being given in section, only one engine can be shown. The
cylinders of this engine are each 14 inches diameter; the length of the
stroke of the piston is 21 inches. There are two sets of driving wheels, 5
feet diameter, with outside connections.

[Illustration: Fig. 29.]

132. _Q._--What is the tender of a locomotive?

_A._--It is a carriage attached to the locomotive, of which the purpose is
to contain coke for feeding the furnace, and water for replenishing the
boiler.

133. _Q._--Can you give examples of modern locomotives?

[Illustration: Fig. 30.]

[Illustration: Fig. 31.]

_A._--The most recent locomotives resemble in their material features the
locomotive represented in fig. 29. I can, however, give examples of some of
the most powerful engines of recent construction. Fig. 30 represents
Gooch's express engine, adapted for the wide gauge of the Great Western
Railway; and fig. 31 represents Crampton's express engine, adapted for the
ordinary or narrow gauge railways. The cylinders of Gooch's engine are each
18 inches diameter, and 24 inches stroke; the driving wheels are 8 feet in
diameter; the fire grate contains 21 square feet of area; and the heating
surface of the fire box is 153 square feet. There are in all 305 tubes in
the boiler, each of 2 inches diameter, giving a heating surface in the
tubes of 1799 square feet. The total heating surface, therefore, is 1952
square feet. Mr. Gooch states that an engine of this class will evaporate
from 300 to 360 cubic feet of water in the hour, and will convey a load of
236 tons at a speed of 40 miles an hour, or a load of 181 tons at a speed
of 60 miles an hour. The weight of this engine empty is 31 tons; of the
tender 8-1/2 tons; and the total weight of the engine when loaded is 50
tons. In one of Crampton's locomotives, the Liverpool, with one set more of
carrying wheels than the fig., the cylinders are of 24 inches diameter and
18 inches stroke; the driving wheels are 8 feet in diameter; the fire grate
contains 21-1/2 square feet of area; and the heating surface of the fire
box is 154 square feet. There are in all 300 tubes in the boiler of 2-3/16
inches external diameter, giving a surface in the tubes o