running northward between the Gy-Parané and the Juruena; he could only guess where it debouched, believing it to be into the Madeira, although it was possible that it entered the Gy-Parané or Tapajos. The region through which it flows was unknown, no civilized man having ever penetrated it; and as all conjecture as to what the river was, as to its length, and as to its place of entering into some highway river, was mere guesswork, he had entered it on his sketch maps as the Rio da Dúvida, the River of Doubt. Among the officers of the Brazilian Army and the scientific civilians who have accompanied him there have been not only expert cartographers, photographers, and telegraphists, but astronomers, geologists, botanists, and zoologists. Their reports, published in excellent shape by the Brazilian Government, make an invaluable series of volumes, reflecting the highest credit on the explorers, and on the government itself. Colonel Rondon’s own accounts of his explorations, of the Indian tribes he has visited, and of the beautiful and wonderful things he has seen, possess a peculiar interest.
