e just sipping from their last cups of coffee when,
even in the dining room, there reached their ears the muffled sound of
gunfire from the bay.

"What's that?" demanded Radwin. "I want to hear the rest of that!"

He hurried through the dining room to the front of the lobby.

"There it goes," he cried, as Rhinds, puffing somewhat, joined him.
"First, the gunfire, then seven long whistles, followed by--wait!"

As the whistling ceased another gun boomed forth.

"That's the emergency signal, to call all hands back who belong on
submarines," uttered Radwin, wheeling about. "We must get our hats and
coats, and hustle down to the water front."

Radwin, had in truth, read the signal aright. It was the signal that
the naval board had announced in case, at any time, there should be
sudden, official news for the officers and crews of the rival submarines.

"What can it be, I wonder?" pondered John Rhinds, as they hurried
through a street that led to the pier.

"Probably some test in which the board wants us to start without any
preparation," replied Radwin.

"I wish I knew what it was," muttered Rhinds.

"That's just the way every man-jack aboard the submarine boats is
feeling about it," jeered Radwin. "Jove, I hope the test, to-day, is
one in which we stand a chance to beat the Pollard crowd!"

Jacob Farnum had just started from the "Hastings," in a shore boat, when
the first gun boomed forth. The shipbuilder had been on his way to see
his friend, at the hospital, when he heard the first gun. Stopping the
rowers, he quickly comprehended when the whistle blasts started. He
accordingly directed that he be put back alongside the "Hastings."

Jack, Hal and Eph had come tumbling up on deck at the first realization
of the signal. Grant Andrews and his men were no longer on board,
having gone, at daylight, to their boarding house on shore.

"What do you suppose is in the air, Jack?" called Mr. Farnum.

"I don't know, sir. But whatever it is, we're ready. We can start, on
anything, at the drop of a handkerchief. Gasoline tanks full,
compressed air by the cubic yard, storage batteries charged."

"It would be hard to catch you youngsters unprepared," laughed the
shipbuilder, appreciatively.

They were still on deck, waiting and wondering, when they saw the
president and secretary of the Rhinds company put off from shore in
haste.

"They don't mean to be left," sneered Eph.

"They're pretty badly left alread