h by
its size, recalled antediluvian monsters.

It drew near with long leaps; Shandon and the doctor fired at the same
time, and suddenly the report of the pieces agitated the air and
produced an unlooked-for effect.

The doctor gazed attentively, and could not help bursting out
laughing. "It's refraction!" said he.

"Refraction!" cried Shandon.

But a terrible cry from the crew interrupted them.

"The dog!" shouted Clifton.

"The dog-captain!" repeated his companions.

"It's he!" cried Pen.

In fact, it was the dog who had burst his bonds and had made his way
to the surface of the ice through another hole. At that moment the
refraction, by a phenomenon common in these latitudes, exaggerated his
size, and this had only been broken by the report of the guns; but,
notwithstanding, a disastrous impression had been produced upon the
minds of the sailors, who were not very much inclined to admit any
explanation of the fact from physical causes. The adventure of the
Devil's Thumb, the reappearance of the dog under such peculiar
circumstances, completely upset them, and murmurs arose on all sides.

CHAPTER XII.
CAPTAIN HATTERAS.

The _Forward_ was advancing rapidly under steam between the ice-fields
and the mountains of ice. Johnson was at the helm. Shandon was
examining the horizon with his snow-spectacles; but his joy was brief,
for he soon saw that the passage was blocked up by a circle of
mountains.

Nevertheless, he preferred to take his chances with pushing on, to
returning.

The dog followed the brig on the ice, but he kept at a respectful
distance. Only, if he lagged too far, there was to be heard a singular
whistle which at once brought him on.

The first time that this whistle was heard, the sailors looked around;
they were alone on the deck, talking together; there was no unknown
person there; and yet this whistle was often repeated.

Clifton was the first to take alarm.

"Do you hear that?" he said; "and do you see how the dog starts as
soon as he hears it?"

"It's past belief," said Gripper.

"Very well!" cried Pen; "I'm not going any farther."

"Pen is right," said Brunton; "it's tempting Providence."

"Tempting the Devil," answered Clifton. "I should rather give up all
my share of the pay than go on."

"We shall never get back," said Bolton, dejectedly.

The crew was exceedingly demoralized.

"Not a foot farther!" cried Wolston; "is that your opinion?"

"Yes, yes!" answer