The life of George Stephenson, railway engineer - Lighthouse ...

CHAP. XII.] IMPEOVEMENT OF THE RAILROAD. 135
locomotive were made stronger. But the most ingenious and
original contrivance embodied in this patent was the substitute
for springs which was devised byl^r. Stephenson. He contrived
an arrangement by which the steam generated in the boiler was
made to perform this important office ! The means by which
this was effected were so strikingly characteristic of true mechan-
ical genius, that we would particularly call the reader's attention
to this ingenious device, which was the more remarkable, as it
was contrived long before the possibility of steam locomotion
had become an object of parliamentary inquiry or even of public
interest.
It has ah-eady been observed that up to, and indeed for some
time after, the period of which we speak, there was no such class
of skilled mechanics, nor were there any such machinery and
tools in use as are now at the disposal of inventors and manufacturers.
The same difficulty had been experienced by Watt
many years before, in the course of his improvements in the
steam-engine ; and on the occasion of the construction of his
first condensing engine at Soho, Mr. Smeaton, although satisfied
of its great superiority over Newcomen's, expressed strong
doubts as to the practicability of getting the different parts
executed with the requisite precision; and he consequently
argued that, in its improved form, this powerful machine would
never be generally introduced. Such was the low state of the
mechanical arts in those days. Although skilled workmen were
in course of gradual training in a few of the larger manufactur-
ing towns, they did not, at the date of Stephenson's patent,
exist in any considerable numbers, nor was there then any
class of mechanics capable of constructing springs of sufficient
strength and elasticity to support a locomotive engine ten tons in
weight.
The rails then used being extremely light, the road soon became
worn down by the traffic, and, from the inequalities of the
way, the whole weight of the engine, instead of being uniformly
distributed over the four wheels, was occasionally thrown almost
diagonally upon two. Hence frequent jerks of the locomotive,
and increased stress upon the slender road, which occasioned
numerous breakages of the rails and chairs, and consequent in-
terruptions to the safe working of the railway.