Theodore Roosevelt (18581919). Through the Brazilian Wilderness. 1914.
rubbermen. The Rio Branco entered from the left at 9° 38. Our camp at 8° 49 was nearly on the boundary between Matto Grosso and Amazonas. The confluence with the Aripuanan, which joined from the right, took place at 7° 34. The entrance into the Madeira was at about 5° 20 (this point we did not determine by observation, as it is already on the maps). The stream we had followed down was from the rivers highest sources; we had followed its longest course.