was again continued it had a different melody. The
wheels, if such they were, seemed to turn with smoothness, and they felt
a sudden inclination in the seats on which they were sitting.

"What do you suppose has happened?" asked Ralph.

"The electric mechanism has been hitched to the propeller, and, if I am
not mistaken, we are going down," said the captain.

"It did feel as though the forward end dipped down a moment ago," said
Alfred.

Another wait for a half-hour, and then a most peculiar sound reached
their ears. Simultaneously, the ship seemed to stop and go on. Again
voices were heard, and the same reaction in the hull of the submarine
was felt, accompanied by the dull noise, as before.

"They have just fired two torpedoes," said the captain.

CHAPTER IV

THE TERRORS IN THE DARK ROOM OF AN UNDERSEA BOAT

Imagine yourself locked in a compartment, barely large enough to stretch
yourself out straight, in a ship under the sea, in total darkness,
knowing that should any one of the hundreds of things within that ship
go wrong, it would mean a plunge to the bottom of the sea, beyond the
help of all human aid.

The danger to them was just as great while on the surface of the water,
for the guns mounted on most vessels at this time, would make the
submarine a legitimate prey. One shot would be sufficient, for ingenuity
has not yet found a way to quickly stop a leak in a submarine. Such a
vessel, when once struck, dare not dive, for that would quickly fill the
interior of the vessel with water.

It must, in that case, remain afloat, subject to the hail of shot which
must follow, their only salvation in that event would be to hoist the
white flag. Few, if any submarine commanders have done so, and even
should that occur, it would not prevent the hull from being riddled
before the fact could be made known. The three-inch guns mounted on
most of the merchantmen, with an effective range of three miles, could
tear the weak hull of a submarine to pieces at a single shot, and all
would be sure to go down before help could arrive from the attacking
steamer.

"The machinery seems to go very slow now," remarked Ralph.

"They may be cautiously coming to the top," replied the captain.

"Did you hear that peculiar noise?" said Alfred, as he laid his hand on
the captain's arm.

"That was plainly a shot from a ship," said the captain.

"Do you think we could hear firing through all this metal?" asked Ralph.

"M