radually disappearing beneath the
snow. But at length they seemed to lose patience, for the doctor saw
them begin to tear away the ice and snow they had heaped up.

"Good!" he said to the captain, who was standing near him.

"What are they doing?" he asked.

"They seem to be trying to destroy what they have done and to get to
us! But they'll be destroyed first! At any rate, there is no time to
lose."

The doctor made his way to the place where the mine was to be laid;
then he enlarged the chamber all the height and breadth of the slope;
a layer of ice, only a foot thick at the outside, remained; it had to
be supported lest it should fall in. A stake resting on the granite
soil served as a post; the fox's body was fastened to the top, and a
long knotted cord ran the whole length of the gallery to the magazine.
The doctor's companions followed his orders without clearly
understanding his intention.

"This is the bait," he said, pointing to the fox.

At the foot of the post he placed a cask holding about a hundred
pounds of powder.

[Illustration]

"And here is the charge," he added.

"But," asked Hatteras, "sha'n't we blow ourselves up at the same
time?"

"No, we are far enough off from the explosion; besides, our house is
solid; and if it is hurt a little we can easily repair it."

"Well," continued Altamont; "but how are you going to set it off?"

"This way. By pulling this cord we pull over the post which holds up
the ice above the powder; the fox's body will suddenly be seen on the
slope, and you must confess that the starving animals will rush upon
this unexpected prey."

"Certainly."

"Well, at that moment I shall explode the mine, and blow up guest and
dinner."

"Well, well!" exclaimed Johnson, who was listening eagerly.

Hatteras had perfect confidence in his friend, and asked no question.
He waited. But Altamont wanted it made perfectly clear.

"Doctor," he began, "how can you calculate the length of the fuse so
exactly that the explosion will take place at the right moment?"

"It's very simple," answered the doctor; "I don't make any
calculation."

"But you have a fuse a hundred feet long?"

"No."

"Shall you set a train of powder simply?"

"No! that might fail."

"Will some one have to volunteer and light the powder?"

"If you want any one," said Johnson, eagerly, "I'm your man."

"It's not necessary, my friend," answered the doctor, grasping the
boatswain's hand; "our five li