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

362 LIFE OF GEOKGE STEPHENSON. Lchaf. xxix.
action, and, consequently, not to be depended upon. At best, it
was but a modification of the stationary-engine system, which
experience had proved to be so expensive that it was gradually
being abandoned in favour of locomotive power. In fact, Mr.
Stephenson's first verdict, " It wont do," proved correct ; and, by
the end of 1848, the whole of the atmospheric tubes were pulled
up—including Mr. Brunei's immense tube on the South Devon
Railway * —to make room for the locomotive engine.
About the year 1840, the fast school propounded another set
of views respecting railways, which were entirely opposed to the
practice and experience of Mr. Stephenson. They promulgated
the idea that undulating railways of uneven, and even severe
gradients, were as favourable for working as flat lines. Mr.
Stephenson, throughout his professional career, was the unvary-
ing advocate of level railways, in preference to more direct but
uneven lines. His practice was to secure a road as nearly as
possible on a level, following the course of the valleys when he
could do so, and preferring to go round a difiiculty rather than
to tunnel through it or run over it,—often making a considerable
circuit in order to obtain good workable gradients. He studied
so to lay out his lines, that minerals and merchandise, as well as
passengers, could be hauled along them in heavy loads, at a com-
paratively small expenditure of locomotive power. He saw
clearly that the longer flat line would eventually beat the shorter
line of steep gradients, as respected paying qualities. It was
perfectly clear to him that there must necessarily be a great
waste of power in overcoming the irregularities of a heavy line.
Thus, Mr. Stephenson had ascertained, by experiments made at
Killingworth many years before, that the locomotive works at
only half its power where it has a rising gradient of 1 in 260 to
overcome ; and when the gradient is so high as 1 in 100, not less
than three fourths of the propelling power of the engine is sac-
rificed in ascending the acclivity. Mr. Stephenson urged that,
after all, the power of the locomotive was but limited; and,
although he had done more to increase its working qualities than
* During the last half-year of the atmospheric, experiment on this line, there
was an expenditure of 2,487/. beyond the gross income of 26,rS2t, or about 9|
per cent.