iar island, "you have the most wonderful boat on earth, and Uncle
Sam has _got_ to have it. My report goes in to Washington to-morrow and
you can guess what it will contain."

"Thank you," said the inventor simply, extending his hand.

CHAPTER XXIX.

INTO THE JAWS OF DEATH.

"That's queer, Rob!"

"What's queer, Merritt, the way you've been sitting and staring for the
last ten minutes?"

"No; that odd noise. Don't you hear it?"

The two lads were seated in the cabin of the submarine on "night guard
duty," as it was called. Following the anxious days when Berghoff had
made affairs on the island so filled with uneasiness for the Scouts and
their friends, this sentry duty had been regularly maintained.

On this particular night the task had fallen to Rob and Merritt. There
was nothing very arduous about it, the only duty involved being to keep
ears and eyes open. Both lads had been engrossed in books dealing with
their favorite subjects when Merritt called Rob's attention to the odd
sound he had noticed.

"Maybe my ears are not quite so sharp as yours, old boy," said Rob,
after an interval of listening. "I've got a slight cold, anyhow, and
perhaps that's why I don't hear so readily."

"Possibly so."

"You are sure you weren't mistaken?"

"Think I'm hearing things?" indignantly responded Merritt. "No, siree,
I'm willing to bet. Hark! There it is again!"

"By Hookey! I heard it that time, too. What can it be?"

"Hush!"

The noise was a most peculiar one. It seemed to be a sort of scraping on
the outside of the submarine's hull. The diving craft was anchored at
some distance from the shore, so as to be more readily prepared for a
projected run the following day. This made the noise all the more
inexplicable, as, had the craft been in the shed, it might have been
caused by the inventor or the ensign paying a night visit to see that
all was well, which they sometimes did.

"Perhaps it's a log bumping against the side."

"No; it appears to come from under the water."

"That's so," agreed Rob; "tell you what, Merritt, it's up to us to
investigate."

"Yes, let's go on deck and see what we can find out."

Together the two lads climbed the steel stairway leading to the conning
tower, and presently emerged on the rounded steel back of the diving
craft. They stood here for a minute or two, trying to get their eyes
used to the sudden change from the bright light of the cabin to the inky
darkness of the