to come with me. As a mining engineer, you will often be
called upon to perform similar unpleasant and dangerous tasks."

"I was afraid, and didn't want to come one bit," said Derrick, with a
nervous laugh.

"That doesn't make any difference. I was afraid too, but we came all the
same. The proof of your courage is not whether you are afraid to do a
thing or not, but whether or not you do it."

So Derrick's courage was tested, and withstood the test, which was
indeed fortunate; for, within a short time, he was to be placed in a
position that would try the courage of the bravest man in the world.

CHAPTER XVI

BURSTING OF AN UNDERGROUND RESERVOIR

Upon reaching the surface that evening, Derrick and the mine boss found
that the weather had greatly changed since noon and that a storm
threatened. It set in that night, and the rain poured down in a steady,
determined sort of way, as though it had made up its mind that this
time, at least, the earth should be thoroughly watered.

When Derrick joined the other miners at the mouth of the slope in the
morning, it was still raining, and as they were lowered into the
underground world, the men joked with each other about getting in out of
the wet, and pitied the poor fellows who were obliged to work
above-ground on such a day.

Descending the second slope into the lowest level of the mine, Tom Evert
and his party made an examination of the place in which they were to
work. The new excavations on this level were of limited extent, work
having only recently been begun on them; but a powerful pump had been
placed at the top of the slope leading down into them, and it was to
bring the accumulated water in the old workings within reach of it that
the mine boss had sent them down.

Going up the old gangway, past the chamber at the foot of the air-shaft
which Derrick had such good reason to remember, they soon came to the
fallen mass of rock, coal, and earth through which they were to cut a
channel and insert a pipe for the release of the water beyond. The
material was too loose for blasting, so the work had to be done with
pick and shovel, and the debris removed with wheel-barrows, and
distributed along the gangway. It was hard, dangerous, and exhausting
work, and at the end of three days Derrick was heartily tired of it.

Still the rain poured steadily down, and people in the upper world began
to talk of danger from floods, and great damage to the ungathered crops.
E