id, "Harry has the reputation
of being the most knowing, and at the same time the most perverse, mule
in the mine. I believe though he only shows bad temper to those who
abuse him, and I have selected you to be his driver because I know you
will treat him kindly, and give him a chance to recover his lost
reputation. If he does not behave himself with you, I shall put him in
the tread-mill. Now stand there out of the way for a few minutes, and
then I will show you where you are to work."

Derrick did as he was directed, and quickly found himself intensely
interested in the strange and busy scene before him. The travelling-road
entered the mine in a large chamber close beside the foot of the slope
that led upward to the new breaker. From this chamber branched several
galleries, or "gangways," in which were laid railway-tracks. Over these,
trains of loaded and empty coal-cars drawn by mules were constantly
coming and going. By the side of the track in each gangway was a ditch
containing a stream of ink-black water, flowing towards a central well
in one corner of the chamber, from which it was pumped to the surface.
Opposite to where he stood, Derrick saw the black, yawning mouth of
another slope, which, as he afterwards learned, led down into still
lower depths of the mine. The men around him were handling long bars of
railroad iron, which they were loading with a great racket on cars, and
despatching to distant gangways in which new tracks were needed. Two
large reflector lamps in addition to the miners' lamps made the chamber
quite bright, and with all its noise and bustle it seemed to Derrick the
most interesting place he had ever been in. He was sorry when the mine
boss called and told him to bring along his mule and follow him.

They entered one of the gangways, leading from the central chamber,
which the mine boss said was known as Gangway No. 1. He also told
Derrick something about his mule, and said that by its last driver, Bill
Tooley, the poor animal had been so cruelly abused that he had sent it
to the surface for a few days to recover from the effects.

"I guess he has recovered," said Derrick, "judging from the way he
brought me into the mine."

They had not gone very far before they came to a closed door on one side
of the gangway beyond which the mule absolutely refused to go, in spite
of all Derrick's coaxings and commands.

"It is the door of his stable," said the mine boss, who stood quietly
looking