All this had not taken many minutes. It was an act of desperation on the part of Frank, but he was determined to save Bob or perish. Fortunately the smoke did not descend just at that moment, but was floating up from the summit, so that the edge of the crater could be seen, with a dull yellow gleam, caused by the sulphur that lay mingled with the sand.

Frank had seen a prostrate figure. It lay on the sand beyond the edge of the lava blocks. His first feeling was one of surprise that Bob had succeeded in penetrating so far; his next was one of horror for fear that he might be beyond the reach of help. With frantic haste he rushed towards him, and reaching the spot, he raised Bob in his arms.

He was senseless!

And now, as Frank stood there, close to the perilous edge, the treacherous smoke, which had thus far held back, rolled down once more. To face it was impossible. Frank flung himself down, and buried his face as before, looking up from time to time to see if the smoke was lessening. The time seemed protracted to a fearful length. The dense fumes which penetrated through the thick folds of the clothes which he held over his mouth nearly suffocated him. He began to think that he, too, was doomed.

And where were the others?

Scattered, apart from one another—and thus they had been caught by the rolling smoke. They could do only one thing, and that was what they had done before. Uncle Moses alone refused to yield. He tried to toil on so as to get nearer to his boys. He had a vague idea of getting near to Frank, so as to die by his side. But physical pain was stronger than the determination of his soul, and at length he involuntarily flung himself down, and covered his face.

But at last even that ordeal was passed. The smoke lifted. It rolled away. There was air again for them to breathe. Frank roused himself before the smoke had all passed, and lifting Bob in his arms, carried him swiftly downward. He reached the place where Uncle Moses was standing, gasping for breath; and the other boys who had seen him hurried towards him, and tried to help him carry his senseless burden. Uncle Moses also tried to take Bob in his own arms, and prayed Frank, with tears in his eyes, to let him carry him; but Frank refused them all, and insisted on doing it himself. A few paces more, however, over the lava blocks, showed that Frank's strength would not be sufficient for such a journey. He sank down exhausted by his excessive exertions, and waited a few moments to take breath.

While he was thus recovering his breath, Michael Angelo reached the spot, and explained that there was another place of descent not far off, and led the way towards it. Here they found the side of the cone all covered with loose sand. Down this they went. At every step they sank in up to their ankles, and the sliding soil bore them down, so that for every step they took they were carried the length of two or three steps.

Frank clung to Bob till he had got beyond the reach of the smoke, and then he fell backward, gasping for breath. The others scrambled towards him, eager to help him; and Michael Angelo, who had exerted himself the least of all, and was fresher than any of them, raised Bob in his arms, and said that he would take care of him now. At this Frank gave up his precious burden, and resuming their descent, they were soon at the foot of the cone.

Here they sat down, and Bob was laid upon the sand. With trembling hands they felt for his heart, and found, to their unspeakable, joy, that it was still beating. There was no water near; but they chafed his feet and hands, and did what they could. For a long time their efforts were unavailing; but at last Bob opened his eyes, and drawing a long, breath, looked around him with a face full of astonishment.