851 



Near this alpine lake rise from the same source 

 the Oroonoko and the Rio Idapa, a tributary 

 stream of the Cassiquiare. The lake Amucu* 

 the source of the Mahu, is enlarged into the 

 Mar Dorado, or Laguna Parime. The Rio 

 Branco is no longer connected, except by two 

 of it's smallest tributary streams, with the basin^ 

 from which the Ucamu issues. It results from 

 this arrangement, altogether hypothetical, that 

 the origin of the Oroonoko is in no lake, and 

 that it's sources are entirely independant of lake 

 Parime and the Rio Branco. Notwithstanding 

 the bifurcated source, the hydrographic system 

 of Surville's map is less absurd, than that which 

 is traced on the map of La Cruz. If modern 

 geographers have so long persisted in following 

 the Spanish maps, without comparing them to- 

 gether, we may at least be surprised, that they 

 have not given the preference to the most mo- 

 dern map, that of Surville, published at the 

 expense of the king, and by order of the minister 

 for India, don Jose de Galvez. 



I have now stated, as I announced above, the 

 variable forms which geographical errors have 

 assumed at different periods. I have explained 

 what in the configuration of the soil, the course 

 of the rivers, the names of the tributary streams, 

 and the multiplicity of the portages, may have 

 given rise to the hypothesis of an inland sea in 

 the centre of Guyana. However dry discus- 

 es i2 



