smallest possible quantity. It was this principle that Stephenson
was gradually learning to appreciate more and more at its proper
value; and it was this which finally led him to the very summit of a
great and pre-eminently useful profession. The great advantage,
indeed, of a level railway over an up-and-down ordinary road is
simply that in the railway the resistance and friction are almost
entirely got rid of.

It was in 1810, when Stephenson was twenty-nine, that his first
experiment in serious engineering was made. A coal-pit had been
sunk at Killingworth, and a rude steam-engine of that time had been
set to pump the water out of its shaft; but, somehow, the engine
made no headway against the rising springs at the bottom of the
mine. For nearly a year the engine worked away in vain, till at
last, one Saturday afternoon, Geordie Stephenson went over to
examine her. "Well, George," said a pitman, standing by, "what do
you think of her?" "Man," said George, boldly, "I could alter her
and make her draw. In a week I could let you all go the bottom."
The pitman reported this confident speech of the young brakesman
to the manager; and the manager, at his wits' end for a remedy,
determined to let this fellow Stephenson try his hand at her.
After all, if he did no good, he would be much like all the others;
and anyhow he seemed to have confidence in himself, which, if well
grounded, is always a good thing.

George's confidence WAS well grounded. It was not the confidence
of ignorance, but that of knowledge. He UNDERSTOOD the engine now,
and he saw at once the root of the evil. He picked the engine to
pieces, altered it to suit the requirements of the case, and set it
to work to pump without delay. Sure enough, he kept his word; and