"Can you climb?" chuckled Tommy, throwing the rays of his searchlight
on the boat. "If you can just mount up on that pile of shale and work
your way through the opening between the two levels. This might have
been used as a sort of an air hole a few hundred years ago," he went
on, "but I'll bet that not one out of a hundred of the miners of today
know that there is an opening here!"

Leaving the boat, the boys mounted the pile of shale and were soon
making their way up the rugged face of the shaft in the direction of
the level, which ran along above the one now being flooded.

"Can you find your way out of this dump, now?" asked Will as the boys
stood with their chums at the end of the long passage.





CHAPTER VII

A TREACHEROUS FOE


"There seems to be fewer twists and turns in this level than on the
one below it," Tommy explained, "and I guess we can find our way out
readily enough. If we don't," he went on, "I shall be obliged to eat
a ton or two of coal to keep from starving to death."

"Serves you right!" declared Will. "You had no business getting up in