indicated
the direction of movement, while another gave not only the inclination
of the ship, but its speed as well.

These things were very fascinating to the boys, but their attention was
now attracted to a still more interesting scene. A bell forward gave two
short, quick snaps. Four men sprang forward and stood at attention, two
on each side of the tube at the right of the hold.

"The indicator shows that the submarine is turning," said the captain.
The boys watched the indicator; it had swung around almost half-way.

"There,--look at the inclinometer," said Ralph. "It is moving
upward----"

"Ting! ting!" Two more sharp bells forward. The cylinder was off the
torpedo, and it lay before them exposed.

Three bells more; and now there was feverish haste. An oval door in the
wall ahead was swung open, revealing a round, black hole.

"That is the torpedo tube," said the captain quietly.

The torpedo was moved back three feet, and then again carried forward on
its truck so that the end of the torpedo entered the tube.

One bell more. The torpedo moved into the tube, the breech block, which
in this case was the oval door, closed, and the crew stood at attention.
While thus waiting the boys glanced at the inclinometer and at the
direction indicator.

"See it swing back and forth," said Alfred. "It seems to act queerly."

"Not at all," replied the captain. "Evidently we are chasing a ship
which is zig-zagging, as we did, for the direction dial is constantly
moving."

While thus conversing they were startled by the signal of four bells.
One of the men, reaching forward, touched a button, and the signal could
be heard in the conning tower. That was, evidently, to inform the
commander there that all was in readiness. Everything was expectancy
now. The ship still manoeuvered.

Then, without a warning of any kind, there was a singular dull sound,
which seemed to shake the submarine from stem to stern.

"They have fired it," said Alfred.

"And they are putting in another one."

"If I am not mistaken it is the last one they have," suggested the
captain.

"Why do you think so?" asked Alfred.

"I notice that all the cylinders with the open ends are without
torpedoes, and you will notice that the one they are now putting in is
the last one with the closed end," responded the captain.

"I am glad they haven't any more of them," said Ralph.

Three bells again sounded; the officer at the gun responded, and during