mes wondered why he did so."

"I did notice one thing, though," said Alfred, "and that was, when the
rear end of the submarine shot upward, and the boxes came tumbling
down, that the hull seemed to roll around to the left."

"That was our salvation," replied the captain. "I then knew we had a
chance."

CHAPTER XII

THE DEATH BLOW TO THE SUBMARINE

Let us try to get some idea of the situation. Ahead of the boat on which
the boys were watching the scene, and probably not more than eight
hundred feet distant, was _l'Orient_. Between them was the row of buoys,
as far as the eye could see, stretching from the shore of England to the
coast of France. To their right, and not two hundred feet distant was
the saucy little chaser, which acted as their convoy.

At a point which might be termed midway between the three vessels thus
described, were the two buoys, which moved with spasmodic jerks, due to
the action of the imprisoned vessel below. As they looked along the
bobbing buoys in either direction, small vessels were observed,
patrolling to and fro, in the tiny mast, or lookout of each, being two
or more men, with glasses, constantly scrutinizing the floats as the
ships slowly moved past.

Apparently, at regular intervals, were large ships of war, all of them
in motion. Sailing vessels and steamers, carrying freight, were coming
up the channel, convoyed to the open doors in this giant network which
guarded the channel.

The lieutenant on the chaser backed his vessel toward the submarine and
hailed the captain:

"Do you wish to remain?" he asked.

"The chances of that fellow seem to be pretty slim. I would like to see
the finish of the game; but I suppose we ought to get into port as soon
as possible," answered the captain.

"Then I will give the order to proceed," replied the lieutenant.

The captain nodded, and the boys started for the door.

"One moment!" said the captain. "We may still be able to see an
interesting sight."

The boys rushed out of the door. Glancing up at the deck of the chaser
they could see the marines aboard rushing to the side of the vessel. As
they looked at the buoys it was noticed that they were silent.
_L'Orient_ was slowly backing away from the obvious location of the
submerged vessel.

"They are about to throw a shell," observed the captain.

The remark had hardly left his mouth when an explosion was heard and the
shell could be observed moving upward at a very high ang