hours, and when it was over the adventurers
found themselves several miles nearer their destination--at least
they hoped they were nearer it, for they were going it blind.

Abe declared they were now in the region of the gold valley. They
cruised about for two days, making vain observations by means of
powerful telescopes, but they saw no signs of any depression which
corresponded with the place whence Abe had seen the gold taken from.
At times they passed over Indian villages, and had glimpses of the
skin-clad inhabitants rushing out to point to the strange sight of
the airship overhead. Tom was beginning to reproach himself again
for his carelessness in losing the map, and it did begin to took as
if they were making a fruitless search.

Still they all kept up their good spirits, and Mr. Damon concocted
some new dishes from the meat of the musk oxen. It was about a week
after the fight with the savage creatures when, one day, as Ned was
on duty in the pilothouse, he happened to lock down. What he saw
caused him to call to Tom.

"What's the matter?" demanded the young inventor, as he hurried
forward.

"Look down there," directed Ned. "It looks as if we were sailing
over a lot of immense beehives of the old-fashioned kind."

Tom looked. Below were countless, rounded hummocks of snow or ice.
Some were very large--as immense as a great shed in which a
dirigible balloon could be housed--while others were as small as the
ice huts in which the Eskimos live.

"That's rather strange," remarked Tom. "I wonder--"

But he did not complete his sentence, for Abe Abercrombie, who had
come to stand beside him, suddenly yelled out:

"The caves of ice! The caves of ice! Now I know where we are! We're
close to the valley of gold! There are the caves of ice, and just
beyond is th' place we're lookin' for! We've found it at last!"

CHAPTER XX

IN THE GOLD VALLEY

The excited cries of the old miner brought Mr. Damon and Mr. Parker
to the pilothouse on the run.

"Bless my refrigerator!" exclaimed Mr. Damon. "Are there more of
those savage, shaggy creatures down there?"

"No, but we are over th' caves of ice," explained Abe. "That means
we are near th' gold."

"You don't say so!" burst out the scientist. "The caves of ice! Now
I can begin my real observations! I have a theory that the caves are
on top of a strata of ice that is slowly moving down, and will
eventually bury the whole of the North American continent.