240 CATAEACTS OF THE ORINOCO. 



know of the course of the Rio Branco, which flows from 

 north to south through the basin of the Upper Orinoco ; 

 while that river itself, in tin's part of its course, pursues 

 for the most part an East and West direction. From poli- 

 tical reasons, the Brazilians, since the beginning of the present 

 century, have testified a lively interest in the extensive plains 

 east of the Rio Branco. See the memoir which I drew up at 

 the request of the Portuguese court in 1817," sur la fixation 

 deslimites des Guyanes Francaise et Portuguaise" (Schoell, 

 Archives historiques et politiques, ou Recueil de Pieces 

 officielles, Memoires, &c. T. i. 1818, p. 48-58). Viewing 

 the position of Santa Rosa on the Uraricapara, the course 

 of which appears to have been determined with tolerable 

 accuracy by Portuguese engineers, the sources of the Orinoco 

 cannot be looked for east of the meridian of 65^- from 

 Paris, (63.8' W. long, from Greenwich) . This being the 

 eastern limit beyond which they cannot be placed, and con- 

 sidering the state of the river at the Randal de los Guaha- 

 ribos (above Carlo Chiguire, in the country of the surpris- 

 ingly fair-skinned Guaycas Indians, and 52' East of the great 

 Cerro Duida), it appears to me probable that the upper part 

 of the Orinoco does not really extend, at the utmost, beyond 

 the meridian of 66 from Paris (64.08' W. from Green- 

 wich.) This point is according to my combinations 4. 12 

 West of the little lake of Amucu, which was reached by Sir 

 Robert Schomburgk. 



I next subjoin the conjectures of that gentleman, having 

 given the earlier ones formed by myself. According to his 

 view, the course of the upper Orinoco to the east of Esme- 



