ey had no sooner stepped out on the platform than there was a
commotion in the water.

"They're going to fight up here!" exclaimed Mark.

A big body shot upward and fell back with a splash, rocking the
submarine.

"There's the whale," observed Andy. "But I reckon he won't fight any
more. He's dead."

It was so. The swordfish had conquered, and the lifeless body of the
whale floated on top of the water, only to sink a little later.

"It was a great battle," said Jack. "I'm glad I was inside the ship."

The course was due south, and every minute it seemed to the boys that it
was getting warmer, for they were approaching the equator. Every hour
brought them nearer the south pole, though they were still several
thousand miles from it.

After a while quite a wind sprang up, and as the sea roughened the
professor decided to go down under the surface. The _Porpoise_ sunk as
the tanks filled and, in a little while, the submarine was in calm
water, and was forging ahead at three-quarter speed.

It was three days after the adventure with the whale when, as the ship
was going along at a good rate, that there seemed to be a gradual
slacking in the progress.

"I wonder what Washington is slowing down for," said the professor
rising from the dinner table at which all save the colored man had been
sitting. "I told him to keep right on. He must have seen something
ahead. I'll take a look."

The inventor went to the conning tower, where Washington was steering.

"What are you stopping for?" he asked.

"I'm not slowin' down," replied the colored man. "Guess another ob dem
debil fishes has grabbed holt ob de ship. Dey suttinly am de most
koslostrous conglomerations ob inconsequence dat I eber see."

"You must keep your big words for another time," remarked Mr. Henderson,
who seemed worried. "Hurry to the engine-room and see if the machinery
is all right. We certainly are slowing down, from some cause or other."

The _Porpoise_ was now scarcely moving, though from the vibration it was
evident that the engines were working almost at top speed. Washington
came back and reported that the big screw was revolving properly and
that all the machinery was working well.

"Then we're caught in something," said the professor. "Shut off the
power, Washington, I don't want to strain things."

The ship was now scarcely making a foot a minute, and, a little later,
when the colored man had turned off the engine, the submarine became
st