heavier rails; the working of
the old engine was improved; and a new engine was shortly after built and
placed upon the road, still on eight wheels, driven by seven rack-wheels
working inside them--with a wrought-iron boiler through which the flue
was returned so as largely to increase the heating surface, and thus give
increased power to the engine.

[Picture: Improved Wylam Engine]

As may readily be imagined, the jets of steam from the piston, blowing
off into the air at high pressure while the engine was in motion, caused
considerable annoyance to horses passing along the Wylam road, at that
time a public highway. The nuisance was felt to be almost intolerable,
and a neighbouring gentleman threatened to have it put down. To diminish
the noise as much as possible, Mr. Blackett gave orders that so soon as
any horse, or horses, came in sight, the locomotive was to be stopped,
and the frightful blast of the engine thus suspended until the passing
animals had got out of hearing. Much interruption was thus caused to the
working of the railway, and it excited considerable dissatisfaction
amongst the workmen. The following plan was adopted to abate the
nuisance: a reservoir was provided immediately behind the chimney (as
shown in the preceding cut) into which the waste steam was thrown after
it had performed its office in the cylinder; and from this reservoir, the
steam gradually escaped into the atmosphere without noise.

While Mr. Blackett was thus experimenting and building locomotives at
Wylam, George Stephenson was anxiously studying the same subject at
Killingworth. He was no sooner appointed engine-wright of the collieries
than his attention was directed to the means of more economically hauling
the coal from the pits to the river-side. We have seen that one of the
first important improvements which he made, after being placed in charge
of the colliery machinery, was to apply the surplus power of a pumping
steam-engine, fixed underground, to drawing the coals out of the deeper
workings of the Killingworth mines,--by which he succeeded in effecting a
large reduction in the expenditure on manual and horse labour.

The coals, when brought above ground, had next to be laboriously dragged
by horses to the shipping staiths on the Tyne, several miles distant.
The adoption of a tramroad, it is true, had tended to facilitate their
transit. Nevertheless the haulage was both tedious and costly. W