ould see.

He approached it with caution, but found that he must not risk a near
approach, for he set the loose scoria in motion, and it trickled on
before him, and went over out of sight with a rush.

Anchoring himself as well as he could against a huge block of lava, he
paused to consider whether he should go to right or left, and then
shrank away with a shudder, and began to climb back as fast he could,
for, slight as had been his bearing upon the block, it had been
sufficient to start it off, and, to his horror, it went on gliding down
about twenty yards, and then dropped over the edge.

He stood listening, in the hope of hearing the block stop directly, as
proof of its being only a few feet down, and passable if he lowered
himself and then climbed the opposite edge; but a full minute elapsed
before he heard a dull, echoing roar, which continued for some time,
and, after a pause, was continued again and again, giving terrible
warning of the depth, and his own insignificance upon that mountain
slope.

He now had his first suggestion of panic--of how easily, in the face of
so much peril, anyone could lose his head, and rush into danger, instead
of escaping the risks by which he was surrounded. For his strong
impulse now was to start into a run, and to begin to ascend the slope
diagonally. But at the first dozen steps, he found he was loosening the
ashes, which began to glide toward the chasm faster and faster, and that
if he continued with so much energy, there would soon be a swift rush,
which would carry him with it into the awful gulf.

Warned by this, he stopped, and then proceeded cautiously, going nearly
parallel, but increasing his distance as far as was possible.

The intense heat of the sun combined with that which radiated from the
mountain-side was exhausting to a degree; his thirst grew almost
unbearable, and he fully realised the imprudence of which he had been
guilty in attempting the ascent alone. The only thing now was to
extricate himself from his perilous position, and, after a halt or two
to collect himself and try to make out how much farther the rift
extended, during which he hesitated as to whether it would not be wiser
to go back and try the other way, he started onward again, slowly and
steadily, becoming conscious of a peculiar puff of stifling vapour,
which he felt sure must come from the gaping rift below.

And now the idea came to him that it was impossible that the chasm could
h