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 have been there when he ascended, but had opened during the fresh eruption in which he had so nearly been overwhelmed.
At last, when his sufferings from the heat were growing unbearable, and his head swam with the giddy sensation which supervened, the rift appeared to close in about fifty yards further on. He sheltered his swimming eyes, and endeavoured to steady himself, as, with sinking heart, he tried to make out whether this really were so, or only fancy. But it seemed to be fact, and, pressing cautiously on, he lessened the distance, and then stopped appalled, shrinkingly facing a way of escape to the lower part of the mountain, but one terrible enough to make the stoutest-hearted shiver. For the chasm came to a sudden end, and recommenced two or three yards farther on, leaving a jagged, narrow strip of lava extending bridge-like from side to side.
“I dare not,” he muttered, as he approached slowly, noting the shape, and trying to make out how far down the mass of rock extended, so as to see whether it would prove firm, or only be a crust which might give way beneath his weight, and then— He shuddered, for he knew that whoever ventured upon that narrow pathway did so facing a terrible death.
He looked wildly forward to see if the gap still went on to any distance, and he could trace it till it was lost in a hot haze.