Cub. "You've had your example of
what my mathematical dad can do with such foolish creatures."

"Let him express his doubt," suggested Mr. Perry with a smile; "for,
if a man must doubt, he'd better shout than smother his ideas in a
skeptic pout."

"Yes, get it off your chest, Bud, and then take your medicine,"
advised Hal.

"Well, suppose we find the island and nobody there, how are we going to
know it's the right one?"

This hit the other two boys pretty hard. The possibility of such a
situation had not occurred to either of them. However, Cub preferred to
take it in lighter vein, for he replied:

"By his footprints on the sandy beach. You mustn't have a Crusoe Island
without some footprints, you know."

"The trouble is you're anticipating too rapidly, Bud," Mr. Perry advised.
"Columbus would never have discovered America in that frame of mind."

"All right, I'll change the frame," said Bud. "We'll just go ahead and
see what we shall see."

"We've got to go ahead if Hal's cousin is in peril," declared Cub.

"Do you really believe the Crusoe boy is your cousin, Hal?" asked Bud.

"Of course that's hard to believe, but the evidence points in that
direction," Hal replied.

"At least if he is your cousin, we know now that he wasn't making monkeys
out of us, as that last message, supposed to come from him, made it
appear he was doing," Cub admitted.

"Yes," put in Mr. Perry; "it looks now as if he was telling a straight
story all along."

"If that's true, then he's probably in serious trouble right now," said
Hal.

"Probably a prisoner in the hands of robbers, if not worse," Bud
supplemented.

"Let's go to bed at once and get a good night's rest so that we will be
in condition to put forth our best efforts to find him and rescue him in
the morning," proposed Mr. Perry.

This proposal met with indorsement from all, and in a short time they
were in their berths, employing their best skill to induce sleep under
condition of much mental excitement.

CHAPTER X

The Island-Surrounded Island

Early next morning the Catwhisker left its mooring under the tamarack and
started on the new search for the "Canadian Crusoe's" island.

Guided by the "mathematical chart" prepared with the directions given by
the radio-compass amateur, the crew of the motor boat had little
difficulty in finding the approximate location of the island prison; but
when arrived there, they realized that considerable work was st