"After learning this I am glad we discovered the stone."
A more persistent search was now made, and George's "hole" was really found to exist. It was just as he described it. Everywhere along the hillside were rocks projecting out from the surface, but here was a depression, or hole, fully fifteen feet square, with rocky sides, the wall on the upper side of the hill being fully fifteen feet high, whereas the lower margin of the hole had a wall not over four feet high, so that it will be seen George had no difficulty in getting out after he had recovered from his fall.
The Professor was in the hole in an instant. The growth about the depression was so dense that it made the hole dark, but there was an unmistakable odor of asphaltum. Some of the overhanging branches were trimmed off, and every portion of the walls examined.
"What do you think made this? Was it washed out?"
"Some one dug this hole," was the Professor's response.
"What makes you think it was dug out?"
"There is plenty of evidence to show that. Look at the marks of tools on the walls all about you."
"Do you suppose it was made to get oil?"
"No; but to get metals."
"What kinds, do you think?"