“I agree with you,” said Nat. “It would be vandalism of the worst sort to strip that rock.”
“Oh, I was only joking,” said Joe, with a rather red face.
“Here’s a peculiar-looking building,” went on Joe, a few moments later, as they passed a tower-like structure, higher than the other buildings, and without windows.
“Let us survey it,” said the professor. “See, here is a door. It has fallen in, it is true, but I imagine we can squeeze through.”
By dint of getting on their hands and knees they managed to crawl under the richly carved and broken portal, Nat pausing to notice that the carvings seemed to be of various astronomical bodies.
Within the tower they found themselves standing at the bottom of a tall, narrow, perpendicular shaft. It was, in fact, like looking up a circular chimney. At the top was something which at first sight seemed to be a big glass lens; but the professor pronounced it to be pure crystal.
“This is the most amazing find yet!” he exclaimed with enthusiasm. “I believe that this tower formed a sort of rude telescope, through which different observations were carried on.”
He clasped his hands in scientific fervor. Indeed, they had seen enough that afternoon to turn the brain of the least imaginative man of science!
Nat informed the professor of the carvings he had noticed.
“That settles the matter,” said the professor enthusiastically. “Good heavens, what a find! It has long been a controversy between various scientific men as to whether or no the ancient races understood astronomy in the true sense. The finding of this rude telescope will go far toward—— Gracious! what was that?”