.

"Well, it is for a fact," he admitted with a little dry chuckle; for he
felt really pleased to think that he had held out so long, and forced
Frank to "show his hand."

"Seems to me we ought to have struck something," suggested Frank.

"Do you really mean you think we've come far enough for that?"
questioned Bob.

"I reckon we have, though it's so dark I can't be dead sure. You don't
happen to glimpse anything queer around here, do you, Bob?" and while
speaking Frank, perhaps unconsciously, lowered his voice more or less.

"Nary a thing," replied the other, breathing fast, as if to make up for
lost time.

"And I don't get any whiff of smoke, do you?" continued Frank.

"Oh! you're thinking about that volcano business again, eh?" chuckled
Bob. "Nothing doing, Frank. Gee! we must be up pretty high here!"

"Feels like it," returned the prairie boy, accustomed to the heavier
air of the lower levels at all times. "Makes me breathe faster, you
know. But that was a hot old climb, Bob."

"All black up yonder in the sky, with never a star showing," observed
the boy from Kentucky.

"Oh! we're going to get it, sooner or later," declared Frank,
cheerfully. "Can't escape a ducking, I take it. But here we are, half
way up old Thunder Mountain, and not a thing to show for our work.
That's what I call tough!"

"Got enough?" asked his chum, invitingly.

"You mean of course for to-night only, because you'd never think of
such a thing as giving up the game so early, Bob?"

"Well, I was only going to make a little suggestion," returned the
other.

"Hit her up, then; though perhaps I could guess what it's like, Bob."

"All right then. You know what I mean--and that since we're away up
here, we might as well make up our minds to hunt an overhanging ledge,
and take a nap. But say, what're you sniffing that way for, Frank?"

"Just imagined that I got a faint whiff of smoke; but of course it was
all in my eye," replied the other.

"Was it? I tell you I had a scent of it myself right then," declared
the taller lad, showing signs of considerable excitement.

"Seems to come and go, then, for I don't get it any more. What was it
like, Bob? Did you ever smell sulphur burning?"

"Lots of times, and helped to use it too, disinfecting," replied Bob,
readily. "Spent months with my uncle, who is a doctor in Cincinnati,
during an epidemic, and he often had to clean out rookeries just to
stamp out the disease. But th