lver! In that confined space it sounded terribly loud.

"He's shot him!" cried Mr. Barr.

But Barton had done nothing of the kind. The attack had been utterly
unexpected by him, and as the door banged against him with terrific
force, he had been knocked down. As he fell the revolver exploded;
before he could pull the trigger a second time the powerful young
officer of Uncle Sam's Navy was upon the man. Barton fought like a
wildcat, and with the superhuman strength of those afflicted with
insanity.

At last, however, he was overpowered and, raving incoherently, was tied
hand and foot and carried out to the cabin where he was placed on a
lounge. Mr. Barr, who knew something of medicine, gave him a calming
dose from the submarine's medicine chest, and he became less violent.

"Barton, where did you put that lever?" demanded the ensign.

The man whimpered like a child.

"I--I don't remember," he gasped out.

Consternation showed on every face. Already the air was getting worse
and worse.

The ensign bent over the bound man, who was now crying weakly.

"You must remember, man. You must, I say!" he snapped, in tones that cut
like the crack of a whip. "Think! think! our lives depend upon it!"

"If I knew, I would tell you," murmured the man; "but I don't. I don't
remember."

A stillness like death itself settled on the occupants of the cabin.
Barton had accomplished his insane purpose only too well, it seemed.

CHAPTER XXVI.

WHICH WILL WIN?

Rob's idea was a simple enough one. With his knife he would cut bundles
of branches and then bind them to the sides of the boat with the rope.
This would at least keep the crazy craft afloat and offer him a means of
reaching the shore.

He set to work at once with great enthusiasm, and by dusk his
strange-looking boat was ready to be launched. By placing round branches
under it for rollers and using another branch as a lever, he soon
succeeded in getting it into the water. But it was hard work, and he
paused to eat some of his canned beef before going any further.

To his huge delight the boat, though lopsided and half full of water,
was buoyed up by the branches, and he had no doubt that he could
navigate her with the oars. As soon as he had finished his unappetizing
meal, Rob clambered on board his "ark," as he mentally called her, and
thrust the oars into the rowlocks. The boat was very heavy, and owing to
her waterlogged condition pulled very hard. Worse st