cannibals, and we shall be well treated."

"I don't know about that," said Stump. "They've got no fresh meat on
board; all they gave us yesterday was fishy stuff; and four fine, fat,
healthy fellows----"

"Shut up, Stump," cried Mont; "how often am I to tell you to hold your
tongue?"

"I know I'm only an odd boy, but----"

"Will you be quiet?" exclaimed our hero, taking up a stool
threateningly.

"All right; I won't say anything more."

The doctor was very silent and thoughtful. Mont remarked this, and said:

"How long do you think they will keep us here?"

"I can't tell any more than you, Folsom," replied the professor.

"But what is your opinion?"

"Not a very encouraging one. We have by chance become possessed of an
important secret. If the secret is worth more than our lives, we shall
either be killed or kept prisoners."

"Forever?"

"Yes, forever," answered the professor gravely. "If the secret is not
very serious, we may be landed on some island. I advise that we remain
perfectly quiet and take things as they come."

"May I say a word?" exclaimed Stump.

"Well?" asked Mont.

"I'll get out of this."

"How? It is difficult to break out of a prison on earth, but to get out
of one under the sea is impossible."

"Suppose we kill our jailers and take the key? If four Americans aren't
a match for a lot of niggers, and one Unknown who can't speak any
language, and doesn't belong to any country at all, it's time we shut up
shop!" went on Stump.

At that moment the door opened, and the negro who had before appeared
entered.

Stump instantly threw himself upon him, and, seizing his throat with his
two hands, held him so tightly as almost to strangle him.

But being a powerful man, he soon disengaged himself, and a fearful
struggle ensued between them.

"Help, help!" cried the negro, in excellent English.

Stump let go his hold at this, and fell back laughing.

"So you can talk English!" he cried; "that's all right. I only flew at
you to see what countryman you were. Now, then, tell us all about this
ship, or I'll give you another dose."

Putting his finger to his lips, the negro gave a peculiar
whistle--prolonged and shrill.

This was evidently a signal, for he had scarcely finished when the
Unknown appeared on the threshold.

He was followed by six powerful negroes, all armed to the teeth.

It looked as if Mont and his friends were to be executed on the spot.

CHAPTER XV.

PRIS