"We hear you," said Jack. "And if you think you're crazy, all right.
I don't feel like joining you in the foolish factory yet awhile."
"I more than half believe the darkey's right," muttered Phineas Roebach. "This experience is enough to turn the brain of any man. I don't myself believe half the things we are seeing."
The heat of the sun, as soon as it had well risen, was a fact that could scarcely be doubted, however. They were glad to seek the shade of the fir trees, and the surface of the glacier began to melt with a rapidity that not only surprised, but startled them.
A flood of water, like a great river, began to sweep by the narrow bit of earth on which they were encamped. The roar of the falling water into the crevasse from which they had so fortunately escaped soon became deafening.
They all had to remove their outer garments. The smell of the heated fir branches was like the odor of a forest on a hot August afternoon. Professor Henderson watched the melting of the ice with a serious face. When Mark asked him what he thought threatened their safety, the old scientist replied:
"I am serious, that is true, my boy. I see in this terrible heat the threat of a great and sudden change in this glacier. We must start as soon as the freeze comes on to-night, and travel as fast as we can toward the far end. Mr. Roebach knows the trail, I believe?"
"I've been over it several times; but I must say that the glacier has sunk a whole lot since I was across it before," the oil man declared.
"We can follow the wolves," said Andy Sudds, stoutly. "They knew their way out."
"That is true, we will hope," Professor Henderson said. "For I must state that I believe our peril is very great."
"How so, sir?" Jack queried.