queried Tom.

"I don't know," Jack admitted. "I'm going to pull the end of the burned
fuse out of this stick and see what's the matter."

Suiting the action to the word, Jack slowly extracted the end of the
fuse from the stick of gelatine in which it had been thrust.

"Ha, Ha," he laughed with a motion as if to slap his thigh. Startled, he
caught himself in time. The laughter died away.

"What's the matter, Jack?" inquired Frank.

"I almost dropped one of the sticks," replied Jack.

"Well, what of it?" innocently Tom suggested.

"Nothing of it," Jack gruffly responded. "At least, I might say nothing
of the Fortuna and her crew if I had dropped one of the sticks. They're
only about an inch in diameter and seven or eight inches long, but one
of them is enough to blow this vessel into chunks and the six would have
blown her to little pieces."

"But why would dropping it to the floor have done damage?" persisted
Tom. "I thought it had to have fire to explode it."

"That's where you're wrong," Jack explained. "Most people have the same
idea. Evidently that was also the idea of the villain who planted this
stuff here, for he neglected to put a cap on his fuse."

"What's a cap?" Tom eagerly asked. "I don't know about this."

"I couldn't help but notice it," Jack scorned. "Well, it's just this
way--You see, dynamite will burn without exploding. A very little jar,
however, sometimes is sufficient to set it going and explode it. When
setting off a charge, a cap containing some fulminate of mercury is put
over the end of the fuse. That stuff will explode from fire. When the
fuse burns down to the cap, the cap explodes and the jar of its
explosion sets off the dynamite. See?"

"Thanks," gratefully replied Tom. "Now I'm enlightened. Then the reason
the Fortuna is still here is because the guy forgot to put his cap on
his fuse? Am I now correct?"

"Right you are, Tom," answered Jack. "Are there any further questions?
If not, the class in explosives is dismissed."

"One more, Professor, if you please." Frank had the floor. "What shall
we do with the stuff? We don't want to keep it aboard."

"That's a problem," Jack announced. "We can't merely throw it overboard;
nor we can't leave it in a fence corner. I'll confess I'm puzzled to
know how we shall get rid of it."

"Let's leave it until morning," Tom suggested. "Just now I'm so worn out
I can't think. I wish we had Wyckoff here, I'd put it in his pockets and
then cl