a name to it," said John Dene tersely.

"How do you propose to keep at sea for any length of time without
recharging your batteries?"

"We shall be lying doggo most of the time," was the reply.

"Then in all probability the U-boats will pass over you."

"We shan't be lying at the bottom of the sea, either," said John Dene.

"What!" exclaimed Admiral Heyworth, "but if your motor's cut off,
you'll sink to the bed of the sea--the law of gravity."

"The _Destroyer_ is fitted with buoyancy chambers, and she can generate
a gas that will hold her suspended at any depth," he explained. "This
gas can be liquefied in a few seconds. Her microphone will tell her
when the U-boats are about; it's my own invention."

Sir Lyster looked from one to the other, unable to grasp such
technicalities; but conscious that Admiral Heyworth seemed surprised at
what he heard.

"It's up to you to see that none of your boys start dropping
depth-charges around," said John Dene.

He went on to explain that he proposed a certain restricted area for
operations, and that the Admiralty should issue instructions that no
depth charges were to be dropped on any submarine within that area
until further notice.

"There's one thing I must leave you to supply," said John Dene, as he
leaned back in his chair smoking a cigar. John Dene chewed the end of
a cigar during the period of negotiations, and smoked it when the deal
was struck.

"And what is that?" asked Sir Bridgman.

"I shall want a 'mother'----"

"A mother!" ejaculated Sir Lyster, looking from John Dene to the First
Sea Lord, who laughed loudly. Sir Lyster always felt that Sir Bridgman
should have left his laugh on the quarter-deck when he relinquished
active command.

"A 'mother,'" he explained, "is a kangaroo-ship, a dry-dock ship for
salvage and repair of submarines. Yes, we'll fit you out."

Sir Lyster looked chagrined. He had found some difficulty in mastering
naval technicalities. When war broke out he was directing a large dock
from which vast numbers of troops were shipped to France. He had shown
such administrative genius, that Mr. Llewellyn John had selected him
for the post of First Lord of the Admiralty, with results that
satisfied every one, even the Sea Lords.

John Dene then proceeded to indicate the nature of the alterations he
would require made in the vessel, showing a remarkable knowledge of the
British type of mother-ship.

"You ought either to be shot as