."

But there was no sign of anything stirring, as the unwieldy bait was
allowed to float on between the stern and bow of the canoe; and though
Jack watched, holding his breath at times in his excitement, there was
not a ripple, and the dummy was dragged back alongside.

"Was it past there you saw them?" said the doctor.

"Yes, past there. Try again, Mr Bartlett."

"Oh yes, we'll try till we get one or two," replied the mate. "Mustn't
go back without something to show."

The men, who seemed as eager as so many boys, let the bait go again, and
once more drew it back without result, then a third time, but were no
more fortunate.

"The tide's fallen since you were here," said the mate, after a few
moments' thought. "Pull a few yards farther away from the shore, and
let it go down to the right of the canoe, where the water's deeper, and
jerk it about like a man swimming--at least as near it as you can," he
added in a low voice to Jack and the doctor.

"Oh dear, I wish I was at that end of the boat," muttered Ned, as the
bundle floated down again from the fresh place, and it had not more than
reached the canoe when a thrill ran through Jack, for the calm water was
suddenly disturbed as if by something shooting through it.

"Look out!" said the mate sharply; "don't let him have it--make him
follow it up. See him, Mr Jack?"

"No! Yes, I can see that black thing sticking out of the water."

"Back fin," said the mate.--"Well done, my lad. Steady.--Make the poor
victim swim for his life, Mr Jack, to escape the shark. Capital. Do
you see he is following the dummy?"

"Yes, I see," said Jack in a husky whisper. "Shall I get the lance?"

"No, no, not yet. That's to kill him when he's harpooned. This is a
good big chap, judging by the size of his fin. Look at it sailing along
like a tiny lateen-rigged boat. Oh, he's coming on splendidly. Smells
the meat. That's it; coax him well up astern, Lenny."

"Ay, ay, sir."

And there, as the man hauled upon the line, and the dummy answered to
each jerk with a splash, the black triangular back fin of the shark came
on behind, cutting the water steadily, till the fish was only about ten
feet from where the mate stood in the stern, giving a sharp look to see
that the rings of line he had drawn out of the tub would run clear.

"Don't move, either of you," he said sternly, as he balanced the harpoon
pole in his hand, well above his head.

Jack could hardly keep in h