"Well, that about ends our present career in the Arctic." The Doctor was
speaking to Dave, and emphasized his word with a sigh. "I had hoped we
might do something really big, but Blake will not be out again this
season. He'll get around again all right, but it's a slow process."

Dave sat thinking. Suddenly he jumped to his feet.

"Doctor," he said eagerly, "there's a gob on board who is sure a wonder
at navigation. Don't you think--think, he and I might manage the sub for
you--your trip?"

"H--m." The Doctor grew thoughtful, but a flash of hope gleamed
in his eye.

"Tell you what," he said presently, "there's a considerable ice-floe
between the islands; the north wind brought it down last night. Have your
crew ready for a try-out in the morning."

With a heart that ached from pure joy of anticipation, Dave hurried to an
ancient sealer's bunk-house where his men were housed. "A try-out,
try-out, try-out," kept ringing in his ears. What did it mean if they
were successful? Something big, wonderful, he was sure. Russian gold?
Charting Northeast Passage? North Pole? He did not know, but nothing
seemed too difficult for his daring young heart.

And the next day the try-out came. And such an ordeal as it was! Gobs had
surely never been put to a test like that in any navy-yard training
station! For five long hours they dived and rose and dived again. They
rose suddenly, rose slowly; they tipped, glided, shot through the water.
They passed for miles beneath the ice-floe, to emerge at last and bump a