he ship had come up with
on the voyage, and this was a much larger one than the first, so
that the passengers crowded up to see the somewhat novel sight.

"If they were only good eating now, we might try for a few,"
observed Ned.

"Some folks eat them, but they're too oily for me," observed a
gentleman who had struck up an acquaintance with the boys and Mr.
Damon. "Their skin makes excellent shoe laces though, their oil is
used for delicate machinery--especially some that comes from around
the head, at least so I have heard."

"Wow! Did you see that?" cried Tom, as one large porpoise leaped
clear of the water, turned over several times and fell back with a
loud splash. "That was the biggest leap yet."

"And there goes another," added Ned.

"Say, this ought to bring those two mysterious passengers out of
their room," observed Tom to his chum in a low voice. "Nearly
everyone else seems to be on deck."

"You haven't been able to catch a glimpse of them; eh Tom?"

"Not a peak. I stayed up several nights, as you know, and paced the
deck, but they didn't stir out. Or, if they did, it must have been
toward morning after I turned in. I can't understand it. They must
be either criminals, afraid of being seen, or they ARE the Fogers,
and they know we're on to their game."

"It looks as if it might be one or the other, Tom. But if they are
criminals we don't have to worry about 'em. They don't concern us."

"No, that's right. Split mackerel! Look at that fellow jump. He's
got 'em all beat!" and Tom excitedly, pointed at the porpoises, the
whole school of which was swimming but a short distance from the
steamer.

"Yes, a lot of them are jumping now. I wonder--"

"Look! Look!" cried the man who had been talking to Mr. Damon.
"Something out of the ordinary is going on among those porpoises. I
never saw them leap out of the water like that before."

"Sharks! It's sharks!" cried a sailor who came running along the
deck. "A school of sharks are after the porpoises!" "I believe he's
right," added Mr. Sander, the gentleman with Mr. Damon. "See,
there's the ugly snout of one now. He made a bite for that big
porpoise but missed."

"Bless my meat axe!" cried the odd man. "So he did. Say, boys, this
is worth seeing. There'll be a big fight in a minute."

"Not much of a fight," remarked Mr. Sander. "The porpoise isn't
built for fighting. They're trying to get away from the sharks by
leaping up."

"Why don't they dive, and