he captured U-boat by American and English
naval officers proved it to be one of the very latest and improved
types of German undersea craft. It was a vessel of a thousand tons
displacement and more than three hundred feet long, capable of a
surface speed of twenty knots an hour and propelled by twin engines
of eight thousand horsepower. The hull was constructed of double
steel---virtually one hull within another---and the space between
hulls given over to the storage of fuel oil, thus increasing the
cruising radius of the vessel by permitting the carrying of more fuel.
The periscopes were of the telescopic variety that could be raised and
lowered.

"What do you suppose they will do with our prize?" asked Jack one
afternoon about a week after they had returned from their adventurous
voyage. He was talking to "Little Mack," who was supervising some
repairs to the _Dewey_.

The submarine commander's eyes twinkled. "I reckon they'll turn her
right in against the Germans," was his reply.

"Do you suppose they will man her with a crew from the American fleet?"
pursued Jack.

"Haven't the least doubt of it," answered his chief. "Some of my boys
may be taken to fill up her crew and I wouldn't be a bit surprised if
they light on you.

"But not with my permission," continued McClure after a pause.

Jack was pleased at the compliment and hastened to assure his commander
that he hoped always to remain with him for the war. Jack's brave
fight to save his captain from the sea in the encounter with the
floating mine, together with the experiences they had shared the last
two weeks, had endeared these two to each other, and while there was
a difference of some ten years in their ages, they were close friends.

Commander McClure's surmises as to the disposition of the U-boat were
correct, as subsequent events showed. Chief Engineer Blaine and his
staff of the _Dewey_ were assigned to the U-boat with orders to
familiarize themselves with the operation of the vessel as quickly
as possible. American deck guns were being substituted for the
German guns and alterations being made in the torpedo tubes to
accommodate made-in-america torpedoes.

Returning to the naval station one afternoon from shore-leave, Commander
McClure drew Jack aside to announce briefly that he had just received
orders transferring him from the _Dewey_ to command of the U-boat.
Executive Officer Cleary, with a portion of the _Dewey's_ crew, had
been d