y to the pole," he announced.

"How can you tell?" asked Mark.

"Because we have just crossed the equator. We went over the imaginary
line three minutes ago."

"I was wondering what made it so warm," said Jack.

"I guess you dreamed it was hotter," spoke the professor. "It has been
just as hot as this for the last few days. Crossing the line makes no
difference."

"Then we are really in the southern hemisphere now," said Mark.

"That's where we are," replied Mr. Henderson.

He put his instruments away.

"Well, we may as well go below the surface again," he remarked.

"Come quick! Hurry up!" yelled Washington from the deck. "Dar's a
shipwreck up heah! Somebody's on it!"

CHAPTER XV

THE STRANGE SHIPWRECK

The professor, followed by the boys and Tom, Bill and Andy hastened on
deck. They saw Washington pointing excitedly off to the west. There,
rising and falling on the easy swell, was the wreck of a large vessel.

She had been a three masted schooner, but now only the stumps of the
masts remained and the craft was rolling to and fro. It had settled low
in the water, and was quite deep by the head, so that, at times, the
waves broke over the bow in a shower of spray.

But what attracted the attention of the adventurers more than anything
else was the sight of two figures near what had been the after cabin of
the ship.

There they stood, frantically waving their hands toward those on the
submarine. Across the water that separated the two craft, there came a
faint hail.

"I suppose they are nearly dead," exclaimed the inventor. "We must save
them."

He ordered the _Porpoise_ sent ahead slowly toward the wreck. The
distance was about half a mile, and was soon covered. As the submarine
approached closer those on the schooner could be observed more plainly.

"One of 'em is a woman!" exclaimed Jack, who was using the glasses.

"Let me see," spoke the professor.

"You're right," he added. "The other is a little girl."

A few minutes later the _Porpoise_ was alongside. The woman and child
came to the rail of the schooner, which was barely five feet above the
waves.

"Can you jump down, or shall I come aboard and get you?" asked Mr.
Henderson seeing the woman hesitate.

"I can jump down, if you will catch the child," said the woman. "Oh I am
so glad you came," she added. "We are almost dead from hunger and
thirst, and the wreck is ready to sink and cannot last many hours
longer."

"Pass the