Thus aided, both boys looked at the exact spot. It was below the snow-line, where only a few of the rocks showed, because of the numerous pines which grew luxuriantly; but, keen as was their eyesight, they were unable to detect the first sign of moving thing or life.
"Try your glasses on it," said Hank.
The boys brought the instruments round in front and levelled them at the point of interest. As they did so they made a discovery. From the very centre of the clump of wood rose a thin, shadowy line of vapor, which was dissolved in the clear air before it ascended more than a few feet above the tree-tops.
"So you obsarve it at last," said the hunter, after they had told what they saw. "Wal, now study it closer, and tell me if you notice anything queer 'bout the same."
Wondering what he could mean, they did as he requested. A minute later Fred said:
"The smoke does not ascend steadily; first it shows plainly, then there is none, and then it shows again."
"Seems to keep it up, eh?"
"Yes, like the puffs from the smoke-stack of a locomotive, only they are a great deal slower," explained Jack; "but the smoke soon dissolves in the clear air."
"Not soon enough, though, to keep you from obsarving what we've been talking about?"
"No; it is too plain to be mistaken."