no limit to the speed of such an engine, if the works could be
made to stand."

Our engine-wright had, however, many obstacles to encounter before he
could get fairly to work with the erection of his locomotive. His chief
difficulty was in finding workmen sufficiently skilled in mechanics, and
in the use of tools, to follow his instructions and embody his designs in
a practical shape. The tools then in use about the collieries were rude
and clumsy; and there were no such facilities as now exist for turning
out machinery of an entirely new character. Stephenson was under the
necessity of working with such men and tools as were at his command; and
he had in a great measure to train and instruct the workmen himself. The
engine was built in the workshops at the West Moor, the leading mechanic
employed being the colliery blacksmith, an excellent workman in his way,
though quite new to the work now entrusted to him.

In this first locomotive constructed at Killingworth, Stephenson to some
extent followed the plan of Blenkinsop's engine. The boiler was
cylindrical, of wrought iron, 8 feet in length and 34 inches in diameter,
with an internal flue-tube 20 inches wide passing through it. The engine
had two vertical cylinders of 8 inches diameter, and 2 feet stroke, let
into the boiler, working the propelling gear with cross heads and
connecting rods. The power of the two cylinders was combined by means of
spurwheels, which communicated the motive power to the wheels supporting
the engine on the rail, instead of, as in Blenkinsop's engine, to
cogwheels which acted on the cogged rail independent of the four
supporting wheels. The engine thus worked upon what is termed the second
motion. The chimney was of wrought iron, round which was a chamber
extending back to the feed-pumps, for the purpose of heating the water
previous to its injection into the boiler. The engine had no springs,
and was mounted on a wooden frame supported on four wheels. In order to
neutralise as much as possible the jolts and shocks which such an engine
would necessarily encounter from the obstacles and inequalities of the
then very imperfect plateway, the water-barrel which served for a tender
was fixed to the end of a lever and weighted, the other end of the lever
being connected with the frame of the locomotive carriage. By this means
the weight of the two was more equally distributed, though the
contrivance did not by any means compensate for