350 Through the Brazilian Wilderness 



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 S° 20' (this point we did not determine by obser- 

 vation, 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. 



