"We'll all go," said David.
"Wait," said Uncle Moses, as the boys were starting. "We must hunt him up as we do in the woods. We can't tell where he is. Let's form a line, an walk as nigh abreast of one another as we can get, an yet far enough away to cover the ground. In that way well be more likely to find him."
At this the party formed themselves in a line, so that about twenty or thirty feet intervened between each. The five thus extended for a long distance. Michael Angelo was at the extreme right, next to him was Uncle Moses, then Clive, then David, while Frank was on the extreme left. In this way they determined to go as far forward as the smoke would permit. The prospect was gloomy enough; but the situation of Bob nerved them all to the effort. Besides, they were encouraged by the fact that the smoke would sometimes retreat far up, exposing the surface to the very crest of the crater. So they advanced, clambering over the rough blocks, and drew nearer and nearer to the summit. At length a heavy mass of black smoke came rolling down. It touched them. It enveloped them. It folded itself over them and under them. Each one fell flat on his face at Michael Angelo's warning, and covered his mouth and nostrils with his handkerchief, so as to keep out the sulphurous vapors. It was almost suffocating; breathing was difficult and painful, and it seemed a long time before the blackness of the darkness was mitigated. But at last the smoke withdrew itself, and the whole party stood up, and looked around painfully for one another, panting heavily, and drawing laborious breaths.
"You can't go any further," said Uncle Moses. "I ain't goin to let you resk your lives, boys. You must all go back, an I'll go for'ard."
"No, uncle; I'll go," cried Frank.
"And I," cried David.
"And I," cried Clive.
"None of you shall go," said Uncle Moses, firmly. "I tell you I'm goin. I order you to stay here, or go back." Uncle Moses was deeply agitated, and spoke with unaccustomed sternness. "Go back," he said; "I'll find Bob, or leave myself there. Go back. D'ye hear?"
He darted forward, and turned to wave his hand at the boys. But Frank had already sprung upward, swiftly and eagerly. Onward he went, going first to the left and then to the right. David and Clive also rushed forward. Uncle Moses toiled after them, calling on them to come back. Michael Angelo followed slowly, looking on with a face of fearful apprehension.
Frank was far ahead. He had come to a place where the lava blocks ended, and the soil was sandy. Here he paused for an instant, and took a swift glance around. He started. He had seen something. He made a quick gesture and then sprang away to the right.