In the distance, and from the direction of their rivals' camp, came the weird chant.
"Well, as long as they stay there we'll be all right," said Tom. "Come on in. I'm anxious to hear what the professor has to say."
"Everything's quiet," reported Ned.
"Then give me your attention," begged the scientist.
Carefully, as though about to exhibit some, precious jewel, he loosened the oiled-silk wrappings and showed a large map, on thin but tough paper.
"This is drawn from the old charts," the professor explained. "I worked on it many months, and it is the only copy in the world. If it were to be destroyed I should have to go all the way back to New York to make another copy. I have the original there in a safe deposit vault."
"Wouldn't it have been wise to make two copies?" asked Tom.
"It would have only increased the risk. With one copy, and that constantly in my possession, I can be sure of my ground. Otherwise not. That is why I am so careful of this. Now I will show you why I believe we are about over the ancient city of Kurzon."
"Over it!" cried Mr. Damon. "Bless my gunpowder! What do you mean?" and he looked down at the earthen floor of the tent as though expecting it to open and swallow him.
"I mean that the city, like many others of Central and South America, is buried below the refuse of centuries," went on the professor. "Very soon, if we are fortunate, we shall be looking on the civilization of hundreds of years ago—how long no one knows.