RESULTS OF THE TRIP 327 



years to a few rubber-men, was utterly unknown to 

 cartographers. It is the chief affluent of the Madeira, 

 which is itself the chief affluent of the Amazon. 



The source of this river is between the 12th and 13th 

 parallels of latitude south and the 59th and 60th 

 degrees of longitude west from Greenwich. We em- 

 barked on it at about latitude 12° 1' south, and about 

 longitude 60° 15' west. After that its entire course 

 lay between the 60th and 61st degrees of longitude, 

 approaching the latter most closely about latitude 

 8° 15'. The first rapids we encountered were in lati- 

 tude 11° 44', and in uninterrupted succession they con- 

 tinued for about a degree, without a day's complete 

 journey between any two of them. At 11° 23' 

 the Rio Kermit entered from the left, at 11° 22' the 

 Rio Marciano Avila from the right, at 11° 18' the 

 Taunay from the left, at 10° 58' the Cardozo from the 

 right. In 10° 24' we encountered the first rubber-men. 

 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 river's highest sources ; 

 we had followed its longest course. 



