red the
invalided engine, and started it afresh.

When he came out of the engine-house, the miners cheered him
vociferously and insisted upon carrying him home upon their shoulders
in triumph!

Steam was now asserting its power everywhere. It was pumping water
from the mines in Cornwall and driving the mills of the manufacturers
in Lancashire. Speculative mechanics began to consider whether it
might not be employed as a means of land locomotion. The comprehensive
mind of Sir Isaac Newton had long before, in his 'Explanation of the
Newtonian Philosophy,' thrown out the idea of employing steam for this
purpose; but no practical experiment was made. Benjamin Franklin,
while agent in London for the United Provinces of America, had a
correspondence with Matthew Boulton, of Birmingham, and Dr. Darwin, of
Lichfield, on the same subject. Boulton sent a model of a fire-engine
to London for Franklin's inspection; but Franklin was too much occupied
at the time by grave political questions to pursue the subject further.
Erasmus Darwin's speculative mind was inflamed by the idea of a "fiery
chariot," and he urged his friend Boulton to prosecute the contrivance
of the necessary steam machinery.[6]

Other minds were at work. Watt, when only twenty-three years old, at
the instigation of his friend Robison, made a model locomotive,
provided with two cylinders of tin plate; but the project was laid
aside, and was never again taken up by the inventor. Yet, in his
patent of 1784, Watt included an arrangement by means of which
steam-power might be employed for the purposes of locomotion. But no
further model of the contrivance was made.

Meanwhile, Cugnot, of Paris, had already made a road engine worked by
steam power. It was first tried at the Arsenal in 1769; and, being set
in motion, it ran against a stone wall in its way and threw it down.
The engine was afterwards tried in the streets of Paris. In one of the
experiments it fell over with a crash, and was thenceforward locked up
in the Arsenal to prevent its doing further mischief. This first
locomotive is now to be seen at the Conservatoire des Arts et Metiers
at Paris.

Murdock had doubtless heard of Watt's original speculations, and
proceeded, while at Redruth, during his leisure hours, to construct a
model locomotive after a design of his own. This model was of small
dimensions, standing little more than a foot and a half high, though it
was sufficiently large to