thought it strange that he
could feel the other trembling.

"Well, what are we going to do about it?" asked Bob, when some time had
passed, and the flood still rushed through the canyon, although in
diminished fury.

"I don't know that we can do anything except camp out right here on
this rock-shelf, and wait for the storm to pass by," replied Frank.

"Even if it takes till morning?" Bob went on.

"Nothing else left to us; and morning won't be so very long coming,
perhaps, Bob. You notice, don't you, that the thunder now is about all
natural?"

"Well, that's a fact," declared Bob. "The geyser has stopped beating
against the inside of the mountain, hasn't it? Got tired of the job,
and quit for another rest, perhaps."

"I've got my idea about that," Frank said "You can see how the water is
still rushing along down there. It must be nearly ten feet deep, and
for some time, now, I don't believe it's varied. Don't you understand
what that means, Bob?"

"Good gracious! do you mean that the old geyser has turned into a
river, and will keep on running like this right along?" cried the other.

"Looks that way to me," Frank replied. "It is a great big syphon, and
once started, the water that has for centuries been wasting in some
underground stream is now flowing down this canyon. Perhaps long ago
it did this same thing, till some upheaval--an earthquake it might have
been--turned things around."

"But I say, Frank!" Bob exclaimed; "If what you tell me turns out to be
true, it looks as if we were bottled up in a nice hole, doesn't it? We
can't get up any farther; and if we go down we'll just have to swim in
a torrent that'll knock us silly. This is what I call tough!"

"Oh! don't look a gift horse in the mouth, Bob. This is a pretty good
sort of a shelf after all; and we'll be glad to stick to it till
morning comes. Time enough then to plan what we're going to do to get
away."

"That's right, and I'm ashamed of complaining," the taller lad burst
out.

"It is a grand old shelf; and if I wasn't afraid of rolling off I
believe I could even snatch a few winks of sleep, wet clothes or not."

"Oh! I'll prop you up with some loose rocks If you want to try it,"
declared Frank; "but the chances are you'll get to shivering. Better
sit up, and whack your arms around as I'm doing every little while. It
makes the blood circulate, you see, and keeps you from going to pieces."

Bob saw the wisdom of this advice.