h."

Stooping, he lifted Paul in his lithe young arms, and with a strength
born of despair began to carry him up the long and devious way that led
to the very top of the lofty building. He had scarcely taken a dozen
steps, and was already staggering beneath his burden, when he stumbled
and nearly fell over some object lying on the floor. With an
exclamation, he set Paul down and picked it up.

It was the crutch, Paul's own crutch; and it was so far above where they
had sat at work that it seemed as though it must have been flung there.

The boys did not pause to consider how the crutch came to be where they
found it, but joyfully seizing it, Paul used it so effectively that they
quickly gained the top of the building and stood at the upper end of the
long slope.

It was a framework of massive timbers supported by high trestle-work,
that led from the highest point of the breaker down the hill-side into
the valley, where it entered the ground. From there it was continued
down into the very lowest depths of the mine. On it were double tracks
of iron rails, up which, by means of an immensely long and strong wire
cable, the laden coal cars were drawn from the bottom of the mine to the
top of the breaker. As a loaded car was drawn up, an empty one, on the
opposite track, went down. The angle of the slope was as steep as the
sharply pitched roof of a house, and its length, from the bottom of the
mine to the top of the breaker, was over half a mile.

This particular slope was provided with a peculiar arrangement by which
a car loaded with slate or other refuse, after being drawn up from the
mine to a point a short distance above the surface, could be run
backward over a vertical switch that was lowered into place behind it.
This vertical switch would carry it out on the dump or refuse heap. The
top of the dump presented a broad, level surface for half a mile, on
which was laid a system of tracks. Over these the waste cars were drawn
by mules to the very edge of the dump, where their contents were tipped
out and allowed to slide down the hill-side. During working hours a boy
was stationed at this switch, whose business it was to set it according
to the instructions received from a gong near him. This could be struck
either from the bottom of the mine or the top of the breaker, by means
of a strong wire leading in both directions from it. One stroke on the
gong meant to set the switch for the mine, and two strokes to set it f