"They had to get out of the North," the drummer mused, "because during the Glacial period an ice-cap miles in thickness covered the world down as far as the dividing line between the British possessions and the United States. That is the way California and Mexico and Central America were populated, anyhow."

"You mean that the immediate ancestors of the people of those countries came from the North," Jimmie criticized. "For all we know, the people who lived before them came from the South. They left no records to show that they ever existed, but the earth was not bare of animal life back of the period our scientists figure from."

"The first ones came from the East, by way of Iceland, Greenland, and Baffinland; from the Eastern continent, and about the vicinity of the Caspian sea, and so kept on South on this continent as the climate grew colder. But we were talking of the people of Mexico. I wanted to show you that they have never been favored as the people of our country have, and that they've got years of national childhood to go through yet before they become a great people."

"Go on and tell me about it," urged Jimmie. "We may learn as much about what's going on here by sitting on this plateau as we could by climbing our heads off."

The boys listened a moment, but there were no suspicious sounds about. The mountain lay as silent under the moon as if no human foot had ever pressed its surface. There were lights far down in the valley, but none on the slopes in view.

"About as far back as the books go in Mexican history," the drummer began, "is the seventh century, even when England wasn't much. About that time the Toltecs came out of the North and took possession of the valley where the City of Mexico now is. They were industrious, peaceful and skilled in many of the arts. They kept their records in hieroglyphics.

"They had a year made up of eighteen months of twenty days each, the other five and a fraction being chucked into the calendar any old way. They knew about the stars and eclipses, and built great cities.

"When they build their temples, it is said, they found ruins of other temples beneath them. And the ones who built the temples, the ruins of which the Toltecs found, doubtless found ruins of temples when they began to dig. It is wonderful. The ages and ages that have gone by, with new civilizations growing up and dying out."

"I feel like I was in a land older than the solar system," said Jimmie. "What became of the Toltecs?"

"They were crowded out by the Aztecs somewhere about the twelfth century. The Aztecs were warlike and cruel. It is said that they murdered twenty thousand victims a year on the altars of their gods. They were able people, too, but murderous in all their instincts. They were cultivated to a degree far above the other peoples of the North American continent at that time, but they lacked the feelings of humanity as expressed to-day.