at derelict's
sunken hull in order to locate it and make your soundings. Now, you
run a big chance of running plumb on to some other stump of a mast.
The 'Hastings' may easily get an injury, from the stump of another
mast, that may tear a real hole in our plates and send us all to the
bottom."

"There's danger to be considered in any submarine game really worth
the while," assented Captain Jack Benson, coolly. "Do you feel then,
Mr. Danvers, that we should be satisfied to drive back to Dunhaven and
content ourselves with wiring the Navy Department news of the derelict
and of her present position?"

Lieutenant Danvers thoughtfully gazed at the young submarine commander's
face.

"No," he muttered, at last. "I think the best thing for a fellow like
you, Jack Benson, will be to wade in and get your revenge! And make
it as complete as you can!"

"All right, sir," nodded Jack. "Thank you. And now, we'll see how
complete a job we can make of it. Mr. Somers!"

"Aye, aye, sir," answered Eph, from below.

"Are you going to consult with your crew?" whispered Danvers.

"They're not the kind of fellows who need consulting," muttered Captain
Jack. "All they want is their orders. Mr. Somers, bring up the
sounding line."

"Aye, aye, sir."

In a moment more young Somers was in the conning tower, and Jack,
sounding line in hand, was out on the platform deck, where Lieutenant
Danvers followed him.

Eph knew, by this time, what was wanted of him. Hal, in the engine
room, was, as yet, ignorant of the game, but all Hal had to do was to
obey engine room signals promptly.

Sending the submarine craft ahead at very slow speed, Eph steered as
close to the bobbing masthead as the young captain deemed safe. Jack
shouted his orders back as he and Lieutenant Danvers crouched over the
nose of the boat.

In the rough sea that was running their work was doubly hard. But Eph
kept the searchlight all the time turned in the direction of the top
of the bobbing mast stump. In a circle they went around it, barely
thirty feet from the broken mast, Jack heaving the sounding lead.

At last he felt it rest on the deck of the sunken derelict. The distance
below was six fathoms--thirty-six feet.

"Now, we've got the line of the hull," called Benson to the lieutenant.
"Our next job is to find how far back this hull runs under the water."

This knowledge, also, was gained, at last. Then Jack Benson, rising,
hastened back to the co