The mysterious loss of a large portion of the treasure of the Incas has never been completely cleared up. By torturing the natives to whom the secret had been entrusted, the Spaniards made two or three discoveries, but there can be little doubt that these finds were only a small proportion of the total amount of the missing hoards, although for years after their occupation of the country the Spaniards spared no pains and hesitated at no cruelty to bring to light the hidden wealth. The story of the boat which put to sea laden with treasure is historical, and it was generally supposed that she was lost in a storm that took place soon after she sailed. It was also morally certain that the Peruvians who left the country when the Spaniards became masters carried off with them a very large amount of treasure into that part of South America lying east of Peru. Legends are current that they founded a great city there, and that their descendants occupy it at the present time. But the forests are so thick, and the Indian tribes so hostile, that the country has never yet been explored, and it may be reserved for some future traveler, possessing the determination of my two heroes, to clear up the mystery of this city as they penetrated that of the lost treasure-ship. It need hardly be said that the state of con-fusion, misrule, and incessant civil wars which I have described as prevailing in Peru presents a true picture of the country at the period in which this story is laid.

From the Preface