peared from view.

"They're running too smoothly!" exclaimed Tommy. "First thing we know,
there'll be a cylinder head blowing out, or a volcanic eruption, or
something of that kind. We've been having things altogether too easy
ever since we landed at Cordova."

"Just listen a moment," Frank said, "I guess there's something going to
happen, right now!"

There came a long, low rumbling sound, apparently moving from east to
west, followed by a tipping of the moraine which almost brought the
horses to their knees.

"It would never answer," Tommy grumbled, "for us to make a trip to
Alaska without bunting into a glacier ready to smash up things!"

"That's not a glacial slide!" Frank said. "It's an earthquake!"

CHAPTER XV

A BREAK IN THE GLACIER

"An earthquake?" repeated Tommy. "I thought they never had earthquakes
in Alaska any more!"

"There are few weeks when there are no earthquakes!" was the reply.

"Well, when's it going to stop quaking?" asked Sam, springing out of the
wagon. "It seems to me that we're getting a sleigh ride!"

The others followed his example, and stood in a moment within fifty feet
of a slowly widening chasm which seemed to run from east to west across
the entire moraine. They had just reached the timber line when the
disturbance began, and now they saw trees a hundred feet in height and
from six to eight inches in diameter dropping like matches into the
great opening in the earth.

"Gee!" exclaimed Tommy. "The breath of the earthquake is enough to
freeze one! I wish I had a couple of fur coats!"

The boy expressed the situation very accurately, for the opening of the
moraine revealed the mighty mass of ice which lay under it. The glacier
which had lain dead under the mat of vegetation for how many hundred
years no one would ever know, showed far down in the great cavern, and a
gust of wind sighing through the ragged jaws laid a chill over the
little party.

Slowly the chasm widened. The ground under the boys' feet seemed to be
unsteady. With a swaying motion it dropped off toward the coast, except
at the very edge of the cavern, which seemed to be doubling down like a
lip folded inside the mouth.

"It strikes me," Frank said, "that we would better be getting the team
out of the track of that chasm! If we don't, the horses and wagon will
take a drop."

Tommy and Sam both sprang forward, but it was too late! The southern
line of the chasm seemed, to drop away for fifty feet