ope to him and his fainting comrades.

Dropping the hammer, and seizing his pick, the burly miner struck a
mighty blow at the wall, and followed it up with others so fast and
furious that the coal fell rattling into the boat, or splashing into the
water in glistening showers. The work of rescue was begun.

As he sat there, Jack Hobson's eye lighted on a long, dark object
floating near them, and calling attention to it, he said,

"Don't you think, sir, that water trough might be bailed out and used as
a sort of boat to establish communication between this point and the
foot of the slope? I have been used to canoes, and believe I could
manage it."

The mine boss said it was a good idea, and he could try if he wanted to.

So the trough, which was simply a long, flat-bottomed box, was brought
alongside, bailed out, and placed in charge of the young man from Black
Run. He made a rude paddle, and during the next two days did capital
service in ferrying miners and tools back and forth between the opposite
sides of the chamber. By this addition to the underground fleet the
large boat could be left at the entrance to the heading, where it proved
most useful as a landing-stage.

The work was pushed with all possible speed, a dozen of the strongest
and most skilful miners, who handled their picks with desperate energy,
taking half-hourly turns each at driving the heading. Behind the miner
who was thus at work, other men passed out the loosened material from
hand to hand, and thus kept the opening clear. Whenever there was no
demand for his services as ferry-man, Jack Hobson took his place among
these workers, and by his cheering words and tireless energy kept up
their spirits and spurred them on to greater efforts.

When they had got about half-way through it was thought best to close
the outer end of the heading with an air-tight door, and place another
ten feet behind it, thus forming an airlock. Fresh air was forced into
and compressed in the heading by means of an air-pump operated from the
flat-boat at the outer end. These precautions were taken for fear lest
when they broke through into the breast the air in it, compressed by the
flood, should rush out with destructive force. It was also feared that,
relieved from its air pressure, the water in the breast would rise and
cut off the escape of any persons who might be in there.

The position of those engaged in the work of rescue was by no means free
from peril. The pu