A couple of lanterns were hung from wooden pins driven in the wall. These lights, being protected by glass, could safely resist the tremendous suction that accompanied each successive convulsion, as the rocks trembled, and the air swept through toward the outer exit.
Only two figures were in sight—a man and a boy. In the latter they recognized little Lopez, the hero of the adventure with the grizzly; and if their suspicions proved true also, the little girl whom Bob had rescued from the anger of the bully, Peg Grant.
The man was a rugged specimen, with long, iron-gray hair. Frank recognized him as Lemuel Smith, whom he remembered to have met several years ago when in a border town with his father.
Smith had always been a rolling stone, a prospector who spent his time in hunting new strikes, and who lived year in and year out in the wild hope of sometime or other hitting it rich. Frank suddenly remembered that Smith had had one daughter, who, he believed, had married a Mexican. And that would make the little girl his grand-daughter.
"They're packing up," remarked Frank, whose quick eye had noticed the fact.
"Perhaps he's done his work here, and means to vamoose the ranch," Bob suggested. "Then again," he added, as another thought raced through his brain, "maybe he doesn't altogether like the looks of things, and wants to get out of this rat-hole before it all goes to smash. He must have been here a long time, and ought to know something about that geyser, Frank."
"There, they have discovered us!" the other exclaimed, as he waved his torch in what he meant to be a friendly way, and kept on advancing.
"Whew! I just hope he doesn't try to fire on us," muttered Bob, who was nervously fingering his rifle, and wondering how dreadful it would feel to be compelled, even in self-defense, to shoot at a fellow human being.
But the old miner held up both hands. It was the Indian peace sign, understood by every savage tribe on the face of the globe.
Quickly the two boys hurried forward, for the first symptoms of another burst of thunder and furious wind began to make themselves felt.