"Maybe it will turn out to be an iron mine instead of a gold mine!" put in Billee, with new hope showing on his face. "Iron's valuable. Not worth as much as gold, of course, but a good iron mine—say, boys, maybe I'll get that self-playin' piano yet."
But again his hopes were dashed.
"It wouldn't pay to work this section even for iron," said Professor
Dodson, and his assistant nodded his agreement.
"Well, then," remarked Nort, "we'll have to keep on raising cattle."
"But we can't do that if these fellows are going to let loose a flood of poison gas and kill them off every now and then!" bitterly cried Bud. "We're beat either way you look at it. Just as you said, Billee, this is Death Valley."
"Tell me more about this!" suddenly suggested the older scientist.
"What is all this about poison gas in tanks killing cattle?"
"I can tell you!" came from Old Tosh. "I know all about it but nobody would ever listen to me. They said I was crazy. But I know! Look here!"
He pointed to a crack, or fissure in the rocky floor of the glen, not far from the cave entrance. It was just such a crack as Bud and his cousins had noticed one day near the place where they had found some dead cattle.
"Listen to that! It's rising!" cried Old Tosh, bending over the crack.
The two professors, the boy ranchers and some of the punchers leaned over and listened. From somewhere down in the depths of the earth came the rustle and swish of running water.