ce, all aglow with a
phosphorescent light, and the runners of the sledge seemed to toss up
a shower of sparks. The doctor ran on ahead to examine this snow, when
suddenly, as he was trying to jump upon a hummock, he disappeared from
sight. Bell, who was near him, ran at once towards the place.

"Well, Doctor," he cried anxiously, while Hatteras and Simpson joined
him, "where are you?"

"Doctor!" shouted the captain.

"Down here, at the bottom of a hole," was the quiet answer. "Throw me
a piece of rope, and I'll come up to the surface of the globe."

They threw a rope down to the doctor, who was at the bottom of a pit
about ten feet deep; he fastened it about his waist, and his three
companions drew him up with some difficulty.

"Are you hurt?" asked Hatteras.

"No, there's no harm done," answered the doctor, wiping the snow from
his smiling face.

"But how did it happen?"

"O, it was in consequence of the refraction," he answered, laughing;
"I thought I had about a foot to step over, and I fell into this deep
hole! These optical illusions are the only ones left me, my friends,
and it's hard to escape from them! Let that be a lesson to us all
never to take a step forward without first testing the ice with a
staff, for our senses cannot be depended on. Here our ears hear wrong,
and our eyes deceive us! It's a curious country!"

"Can you go on?" asked the captain.

"Go on, Hatteras, go on! This little fall has done me more good than
harm."

They resumed their march to the southeast, and at evening they halted,
after walking about twenty-five miles; they were all tired, but still
the doctor had energy enough to ascend an ice-mountain while the
snow-hut was building.

[Illustration: "The doctor had energy enough to ascend an ice-mountain
while the snow-hut was building."]

The moon, which was nearly at its full, shone with extraordinary
brilliancy in a clear sky; the stars were wonderfully brilliant; from
the top of the iceberg a boundless plain could be seen, which was
covered with strangely formed hillocks of ice; in the moonlight they
looked like fallen columns or overthrown tombstones; the scene
reminded the doctor of a huge, silent graveyard barren of trees, in
which twenty generations of human beings might be lying in their long
sleep.

In spite of the cold and fatigue, Clawbonny remained for a long time
in a revery, from which it was no easy task for his companions to
arouse him; but they had to th