519 



considerations it results, that while on the west 

 of the Cassiquiare, between that river, the 

 Atabapo, and the Rio Negro, we find only vast 

 plains, in which rise some monticules and insu- 

 lated rocks; real counter-forts stretch on the 

 east of the Cassiquiare, from N.W. to S.E. and 

 form a continued mountainous territory as far 

 as the 2° of north latitude. The basin only, or 

 rather the transversal valley of Rio Branco, 

 forms a kind of gulph, a succession of plains 



given in Arrowsmith's map, of the sources of the Padaviri, 

 placed in 3° latitude, while in the manuscript maps of Pontes 

 these sources are marked at 1 J°. Heretofore the Daraha, the 

 Padaviri,and the Uaraca,were supposed to join the Rio Branco , 

 having three distinct mouths, and forming a delta of tribu- 

 tary streams. (See Surville's map, which accompanies the Co- 

 rography of Caulin) . The great inundations of Seriveni and 

 Caritamini (lat. 1°— 2° north) have no doubt given rise to 

 the fable of lake Mauvatu, on the map of the Amazon traced 

 by M . Requena, first commissary of the boundaries in the ser- 

 vice of the King of Spain. These inundations, and the uniform 

 assertion of the Indians, that the Rio Mocajahi communi- 

 cates with the Cababury, may also have contributed to the 

 hypothesis of the imaginary lake which Surville places west 

 of the Rio Branco, and which he links at the same time to 

 that river and the Oroonoko (Vol. v, p. 851). I shall here 

 observe, that the lake Amuca of Hortsmann, and the two 

 upper branches of the Rio Branco, the Uraricuera and the 

 Mahu, which is the classical country of Dorado of Ralegh, 

 are found, according to the astronomical observations of Por- 

 tugueze travellers, between the parallels 3° and 4°, while 

 Surville's map enlarged that space from 4° to the equator. 



