CATARACTS OF THE ORINOCO. 215 



they took their rise. After following a westerly and then a 

 northerly course, it runs again to the east, so that its mouth 

 is almost in the same meridian as its source. From the 

 Chiguire and the Gehette as far as the Guaviare the 

 Orinoco flows to the west, as if it would carry its waters to 

 the Pacific. It is in this part of its course that it sends out 

 towards the south a remarkable arm, the Cassiquiare, but 

 little known in Europe, which unites with the Rio Negro, 

 (called by the natives the Guainia), and offers perhaps the 

 only example of a bifurcation forming in the very interior 

 of a continent a natural connection between two great rivers 

 and their basins. 



The nature of the ground, and the junction of the 

 Guaviare and Atabapo with the Orinoco, cause the latter to 

 turn suddenly towards the north. In the absence of correct 

 geographical knowledge, the Guaviare flowing in from the 

 west was long regarded as the true origin of the Orinoco. 

 The doubts raised by an eminent geographer, M. Buache, 

 since 1797, as to the probability of a connection with the 

 Amazons, have I hope been entirely refuted by my expedi- 

 tion. In an uninterrupted navigation of 920 geographical 

 miles I passed through the singular network of rivers, from 

 the Rio Negro, by the Cassiquiare, into the Orinoco ; tra- 

 versing in this manner the interior of the Continent, from 

 the Brazilian boundary to the coast of Caraccas. 



In the upper portion of the basin of the Orinoco and its 

 tributaries, between the 3rd and 4th degrees of north lati- 

 tude, nature has several times repeated the enigmatical 

 phenomenon of the so-called " black waters." The Atabapo, 



