up with the boy.

Then he dove deep down so as to come up under the shark before he could
turn and rush at the boy so near him.

Down went Jack, and presently began to rise, seeing the white belly of the
man eater just above him.

With a fierce upward thrust of his right arm, which held the knife he had
taken from the cook, he plunged the blade into the creature's vitals,
drawing it downward and toward him, and turning his hand as he drew, thus
making a jagged cut, and fairly laying open the shark's belly.

Young Smith, encouraged by Jack's shout, had darted ahead with his little
remaining strength, not again looking back, and knowing too well what was
about to happen when Jack dove.

As the shark, mortally wounded, floated away, to be eaten by others of his
kind, Jesse W. suddenly became faint and felt himself giving out.

Jack arose in a moment, however, and called out cheerily:

"Hold on a moment, young fellow, and I'll be there. You mustn't give out
yet, because they haven't put about to take us aboard."

The younger boy held out till Jack reached him, but seemed about to go
under again when Jack said quickly:

"Here, get on my back and you won't have to swim. I'll tow you all right,
and you can get rested."

"Did you kill him, Jack?" gasped the younger boy, as he obeyed the older
one's instructions.

"Yes, yes, but never mind about that. Don't look behind you, just look
straight ahead. I don't know that there's anything there anyhow, but it is
always a good plan to look the way you're going to avoid accidents."

"You're a funny fellow, Jack," said the other. "You don't want me to see
the sharks and be frightened."

"That's all right, old man, but there are no sharks at present, and if any
come they will be too busy taking bites out of the other to bother me for
a time. H'm! they are putting about. That's all right."

"You can carry me and swim yourself all right, Jack?" asked Jesse W.
"Maybe I can swim a bit myself now."

"Never you mind about that," said Jack. "You just stay on my back till I
tell you to get off," and the boy swam with a good, steady stroke toward
the approaching yacht, keeping a lookout for sharks, as he knew they would
be sure to appear soon, seeming to scent blood for miles.

Without letting the younger boy know that he was on the lookout he kept a
strict watch on all sides for more of the rapacious creatures, and at
length discovered two making for him in different directions