The prospect that greeted their eyes was wonderfully beautiful. The lake itself was some five miles long, but only one in width. As they now approached the shore opposite, they descried a stone jetty, for one side of which the canoes headed, while the barge was brought up on the other. They were disembarked and marched ashore under escort of Prince Huaca and twenty men. The others remained by their craft.

At the end of the jetty a guard house of stone was passed. What surprised the boys beyond measure was to see the half dozen sentries drawn up in military formation, present arms with their silver-mounted muskets as Prince Huaca passed.

“I can’t believe it,” muttered Frank. “Incas presenting arms!”

Mr. Hampton offered a solution.

“Perhaps some adventurer captured by them, as were we, has instructed them in military tactics.”

Ahead through a copse of trees lay a country home of stone, and toward this Prince Huaca bent his steps. On nearer approach they could see the stone was beautifully chiselled, and the house nobly proportioned with a broad portico in front, through the supporting pillars of which they could see a courtyard, around the sides of which the dwelling was constructed.

At the command of Prince Huaca, the guard halted at the foot of a broad flight of stone steps with the prisoners, while the prince mounted and disappeared into a door on the left of the courtyard. The captives now had a chance to look about them. Although about the house, or, better, the mansion itself, no figures were to be seen, there was a constant coming and going in what they took to be the servants’ quarters which lay considerably to the left.

Horses were being watered in one spot, out of a great trough, and then led back to the fields which stretched on every hand. Don Ernesto exclaimed at this sight.

“Those are Argentinian horses,” said he, with conviction. “The early Spaniards who colonized the region of La Plata were enjoined by their monarchs to bring over a certain number of head of horses and of cattle for their own use, and a certain number to be turned loose to breed. Thus the great herds of wild horses and cattle which used to thunder over the Pampas, but since have been largely exterminated or brought under herd, came into existence.”

“And you think——”