Down an Unknown River 327 



stream, which we had just come down, was difficult to 

 traverse; but the governmental and scientific authorities, 

 native and foreign, remained in complete ignorance ; and 

 the rubber-men themselves had not the slightest idea of 

 the headwaters, which were in country never hitherto 

 traversed by civilized men. Evidently the Castanho was, 

 in length at least, substantially equal, and probably supe- 

 rior, to the upper Aripuanan ; it now seemed even more 

 likely that the Ananas was the headwaters of the main 

 stream than of the Cardozo.* For the first time this 

 great river, the greatest affluent of the Madiera, was to be 

 put on the map ; and the understanding of its real position 

 and real relationship, and the clearing up of the complex 

 problem of the sources of all these lower right-hand afflu- 

 ents of the Madiera, was rendered possible by the seven 

 weeks of hard and dangerous labor we had spent in going 

 down an absolutely unknown river, through an absolutely 

 unknown wilderness. At this stage of the growth of 

 world geography I esteemed it a great piece of good 

 fortune to be able to take part in such a feat — a. feat 

 which represented the capping of the pyramid which dur- 

 ing the previous seven years had been built by the labor 

 of the Brazilian Telegraphic Commission. 



We had passed the period when there was a chance of 

 peril, of disaster, to the whole expedition. There might 

 be risk ahead to individuals, and some difficulties and 



* I hope that this year the Ananas, or Pineapple, will also be put 

 on the map. One of Colonel Rondon's subordinates is to attempt 

 the descent of the river. We passed the headwaters of the Pine- 

 apple on the high plateau, very possibly we passed its mouth, al- 

 though it is also possible that it empties into the Canama or Tapa- 

 jos. But it will not be "put on the map" until some one descends 

 and finds out where, as a matter of fact, it really does go. 



