r 1795.

As Mr. Murray had obtained considerable practical knowledge of the
steam-engine while working at Mr. Marshall's, he took principal charge
of the engine-building department, while his partner Wood directed the
machine-making. In the branch of engine-building Mr. Murray very
shortly established a high reputation, treading close upon the heels of
Boulton and Watt--so close, indeed, that that firm became very jealous
of him, and purchased a large piece of ground close to his works with
the object of preventing their extension.[3] His additions to the
steam-engine were of great practical value, one of which, the
self-acting apparatus attached to the boiler for the purpose of
regulating the intensity of fire under it, and consequently the
production of steam, is still in general use. This was invented by him
as early as 1799. He also subsequently invented the D slide valve, or
at least greatly improved it, while he added to the power of the
air-pump, and gave a new arrangement to the other parts, with a view to
the simplification of the powers of the engine. To make the D valve
work efficiently, it was found necessary to form two perfectly plane
surfaces, to produce which he invented his planing machine. He was
also the first to adopt the practice of placing the piston in a
horizontal position in the common condensing engine. Among his other
modifications in the steam-engine, was his improvement of the
locomotive as invented by Trevithick; and it ought to be remembered to
his honour that he made the first locomotive that regularly worked upon
any railway.

This was the engine erected by him for Blenkinsop, to work the
Middleton colliery railway near Leeds, on which it began to run in
1812, and continued in regular use for many years. In this engine he
introduced the double cylinder--Trevithick's engine being provided with
only one cylinder, the defects of which were supplemented by the
addition of a fly-wheel to carry the crank over the dead points.

But Matthew Murray's most important inventions, considered in their
effects on manufacturing industry, were those connected with the
machinery for heckling and spinning flax, which he very greatly
improved. His heckling machine obtained for him the prize of the gold
medal of the Society of Arts; and this as well as his machine for wet
flax-spinning by means of sponge weights proved of the greatest
practical value. At the time when these inventions were made