beetling front of
those high cliffs. They viewed them from their base, and then passing
outward scanned them to the very tops. There was no gorge or ravine
which they did not enter and fully reconnoitre. Many of these there
were, all of them resembling little bays of the ocean, their bottoms
being on the same level with the valley itself, and their sides formed
by the vertical wall of granite.

At some places the cliffs actually hung over. Now and then they came
upon piles of rock and scattered boulders--some of them of enormous
dimensions. There were single blocks full fifty feet in length,
breadth, and height; and there were also cairns, or collections of
rocks, piled up to four times that elevation, and standing at such a
distance from the base of the cliff, that it was evident they could not
have fallen from it into their present position. Ice, perhaps, was the
agent that had placed them where they lay.

None of the three were in any mood to speculate upon geological
phenomena at that moment. They passed on, continuing their examination.
They saw that the cliff was not all of equal height. It varied in this
respect, but its lowest escarpment was too high to be ascended. At the
lowest point it could not have been less than three hundred feet sheer,
while there were portions of it that rose to the stupendous height of
one thousand from the valley!

On went they along its base, carefully examining every yard. They had
gone over the same path with lighter feet and lighter hearts. This time
they were three hours in making the circuit; and at the end of these
three hours they stood in the gap by which they had entered, with the
full and painful conviction that that gap was the only outlet to this
mysterious valley--the only one that could be traversed by human foot!
The valley itself resembled the crater of some extinct volcano, whose
lava lake had burst through this gate-like gorge, leaving an empty basin
behind.

They did not go back through the glacier ravine. They had no hope of
escaping in that direction. That they knew already.

From the gap they saw the white vapour curling up over the spring. They
saw the remaining portion of the precipice that lay beyond. It was the
highest and most inaccessible of all.

All three sat down upon the rocks; and remained for some minutes silent
and in a state of mind bordering upon despair.

CHAPTER THIRTY.

PROSPECTS AND PRECAUTIONS.

Brave men do no