The history of the first locomotives in America. From original ...

TREVITHICK'S ENGINE. 43
to take a fresh step wliere the reversed action of tlie
piston lias lowered it again. The action of the other
leg is precisely similar, hut motion communicated to it
from the first one. Just above the knee of the front leg,
at N, is attached a rod, on which is a toothed rack, R.
Working in it is a cog-wheel, which enters also a second
rack, r, helow it, which is connected by a second rod
with point n of the other leg. "When the piston is driven
out and pushes the engine from the knee, the rack E is
drawn backward, and turns the cog-wheel, which then
draws the lower rack r forward, and operates on the
hind leg precisely as the piston-rod does on the front
one, and thus the legs take alternate steps, and walk on
with the engine.
This locomotive or " mechanical traveller," as it
was termed by its inventor, moved on a railway at the
rate of two and a half miles per hour, with the tractive
force of four horses. Mr. Brunton's machine, however,
never got beyond the experimental state, for, on one of
its trials, it unhappily blew up, killing and wounding
several of the by-standers, was never repaired, but laid
aside as one, of the failures of the times.
These experiments, though failures in their results,
were followed up by a Mr. Blackett, of Wylam, whose
persevering efforts paved the way for the fature labors
of George Stephenson.
To make his experiments Mr. Blackett ordered one
of the locomotives of -the Trevithick patent, and also
employed rack-rails and tooth driving-wheels like
Blankensop's, and had his road altered for the occasion.
This engine was the most awkwardly-constructed ma-
chine imaginable. It had a single cylinder six inches
in diameter, and a fly-wheel working on one side to carry
the cranks over the dead-points. The boiler was of cast-
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