that the intercepted vessel will turn to avoid it. Then the
other submarine, with nothing but its periscope above the water, and on
the other side of the sailing course of the ship, will be in position,
the moment the turn is made, to deliver the shot. That is why the
captain has gone to the other side, as you will notice the vessel is
now going to starboard," said the officer.

The ship had now turned so that it was broadside to the distant
submarine. Not only its conning tower was now visible, but a long black
object fore and aft could be plainly observed.

"Three points to port!" shouted the captain.

The quartermaster swung the wheel around, and the ship seemed to heel
over, so suddenly did the rudder act.

"One point to starboard, and full speed ahead!" was the next order from
the captain.

It seemed that the order had no more than been executed than he again
sang out:

"Two points to port!"

"What is that for?" asked Alfred.

"He is zig-zagging the ship through the sea," replied the officer.

"What for?" inquired Ralph.

"There is another submarine three points to starboard astern."

"Then,--then the captain,----"

"Yes; the one behind us is near enough to reach us if we keep on a
straight course, but the captain has manoeuvered so as to bring him
directly in our wake, and continually changed the target so that the
submarine cannot aim with accuracy," interrupted the officer.

The passengers on the decks below did not need to be told that something
unusual was happening. The changing course of the ship, the unusual
activity on the bridge, the leveling of the glasses to the port side
and to the stern by the different groups, were sufficient warnings of
the presence of the dread monsters.

The submarine on the port side was now coming forward with all the speed
it possessed, and again the captain turned the ship another point to
starboard. The funnels were belching smoke, and sparks flying from the
top. The engineers were putting on forced draft and the ship seemed to
be trembling as it shot through the smooth sea. It was an ideal
condition for the launching of a torpedo.

"Torpedo coming on starboard side!" shouted a voice.

Every one now rushed to the right side of the bridge. There was a shriek
below. From an unexpected quarter the third submarine's periscope was
visible, and a foamy trail, straight as a mark, began to lengthen out
toward their vessel.

"Reverse! Reverse engines!" shouted th