eam-carriage,
William Murdock, the friend and assistant of Watt, constructed his model
of a locomotive at the opposite end of the island--at Redruth in
Cornwall. His model was of small dimensions, standing little more than a
foot high; and it was until recently in the possession of the son of the
inventor, at whose house we saw it a few years ago. The annexed section
will give an idea of the arrangements of this machine.

It acted on the high-pressure principle, and, like Cugnot's engine, ran
upon three wheels, the boiler being heated by a spirit-lamp. Small
though the machine was, it went so fast on one occasion that it fairly
outran its inventor. It seems that one night after returning from his
duties at the Redruth mine, Murdock determined to try the working of his
model locomotive. For this purpose he had recourse to the walk leading
to the church, about a mile from the town. It was rather narrow, and was
bounded on each side by high hedges. The night was dark, and Murdock set
out alone to try his experiment. Having lit his lamp, the water boiled
speedily, and off started the engine with the inventor after it. He soon
heard distant shouts of terror. It was too dark to perceive objects; but
he found, on following up the machine, that the cries proceeded from the
worthy pastor of the parish, who, going towards the town, was met on this
lonely road by the hissing and fiery little monster, which he
subsequently declared he had taken to be the Evil One _in propria
persona_. No further steps were, however, taken by Murdock to embody his
idea of a locomotive carriage in a more practical form.

The idea was next taken up by Murdock's pupil, Richard Trevithick, who
resolved on building a steam-carriage adapted for common roads as well as
railways. He took out a patent to secure the right of his invention in
1802. Andrew Vivian, his cousin, joined with him in the patent--Vivian
finding the money, and Trevithick the brains. The steam-carriage built
on this patent presented the appearance of an ordinary stage-coach on
four wheels. The engine had one horizontal cylinder, which, together
with the boiler and the furnace-box, was placed in the rear of the hind
axle. The motion of the piston was transmitted to a separate crank-axle,
from which, through the medium of spur-gear, the axle of the
driving-wheel (which was mounted with a fly-wheel) derived its motion.
The steam-cocks and the force-pump, as also the bellows