keep on doing the trick for them, I'm afraid
they'll soon guess how it's done. I don't believe, sir, you can fool the
American Navy more than once."

CHAPTER XV

SERVING IN THE CAUSE OF PEACE, NOT WAR

"It seems almost a shame to have to go below," sighed Lieutenant McCrea.

It was evening, the time about nine o'clock. For nearly an hour the
"Pollard" had been running out to sea at something below her full speed.
She was now something like a dozen miles off the coast.

Commander Ennerling had just decided that it would be a good time to test
the diving capabilities of the submarine.

Ventilators were shipped, and all other preparations had been made for
going below the surface.

Eph was left in the conning tower, Lieutenant McCrea with him.

"How far do you want the dive to be made, sir?" asked Jack Benson.

"A depth of forty feet ought to serve the purpose," stated the president
of the board.

"Then, sir, we will make a sloping dive to that depth, then complete the
curve until we strike the surface again," proposed the submarine boy.
"How will that suit you, sir?"

"Excellently," agreed the Navy commander.

"Do you want to take the record with your stop watch?"

"Yes?"

"All ready, sir."

As Captain Jack gave the word he threw open the forward water tanks, so
that water rushed in, tilting the bow of the craft downward. The
"Pollard" moved on a decided slant until Captain Jack read the depth of
forty feet on the gauge. Then, with a barely perceptible rest. On an
even keel, the young submarine expert threw compressed air into the
forward tanks, expelling the water, at the same time admitting water to
the tanks aft.

Gracefully, and with, the precision of a trained living being, the
submarine craft curved upward until Lieutenant McCrea shouted down:

"We're awash, sir"

Benson drove the water from the tanks aft, and the boat rode the waves.

"Now, let us see you run a little lower than awash, with just enough of
the conning tower in the air for the helmsman to see where he is
steering," proposed the president of the board.

Jack went above to relieve Eph at the wheel, while Commander Ennerling
stationed himself beside the boy.

"You may use your searchlight, of course," proposed the commander, "and
proceed just as though you were trying to pick up a battleship of the
enemy without much exposing yourself."

As the broad, bright beam of the searchlight shone out over the waters
ahea