with a hole, or tunnel, about ten feet
high and as broad, but of irregular shape, opening into it, and on the
bottom, or floor, a two-foot iron pipe out of which, at normal times,
ran a stream of water, you will have a good idea of the place into
which our young heroes were to enter.

The tunnel extended all the way through Snake Mountain, curving this
way and that, as a brook curves its way through a meadow. In fact the
tunnel had been made, centuries ago, by a stream forcing its way
through the soft parts of the mountain, and it was this old, hidden,
underground stream-way of which Mr. Merkel had taken advantage to bring
water to Flume Valley.

The stream flowed along the bottom of the tunnel course, leaving room
on either side for persons to walk, as they might walk along the banks
of a stream in the open. The underground river was not more than four
feet wide, and about the same in average depth, but in places it flowed
with a very powerful current.

"Whew! It's black as tar here!" exclaimed Dick, as they walked in past
the pipe, and found themselves in the tunnel proper.

"As bad as the Hole of Calcutta," added Nort, who had read that grim
story of the Sepoy rebellion in India.

"Do you want to back out?" asked Bud, swinging his lantern so that it
cast flickering shadows on the place where water had flowed, but where
there was none now.

"Back out!" cried Nort. "I should say not! Lead on, Macduff!"

And they started off in the blackness of the tunnel, with only the
faint gleams of the lanterns to illuminate their way. What would they
find?

CHAPTER XI

THE RUSH OF WATERS

Echoes of the footsteps of the boy ranchers sounded and resounded as
they tramped along the now dry water-course of what had, only a day
before, been a life-giving stream of water. The rocky and
roughly-vaulted roof overhead gave back the noises like the soundbox of
a phonograph, and the lads had to speak loudly, in places, to make
their voices carry above the echoes. These places were spots where the
vaulted roof of the tunnel was higher than usual.

They had walked on, the semi-circular spot of light at the entrance
near the black pipe growing more and more faint, until it was not at
all visible.

"There she goes!" exclaimed Dick, looking back.

"What?" asked his brother.

"The last gleam of daylight," was the answer. "If anything happens to
our lanterns, so that they go out, and we get mixed up in some branch