GEOLOGICAL PHENOMENA, 93 



Pampas of Buenos Ayres. As the region of forests com- 

 prises at once the plains and the mountains, it extends from 

 18 south to 7 and 8 north,* and occupies au extent of 

 near a hundred and twenty thousand square leagues. This 

 forest of South America, for in fact there is only one, is six 

 times larger than France. It is known to Europeans only 

 on the shores of a few rivers, by which it is traversed ; and 

 has its openings, the extent of which is in proportion to that 

 of the forests. We shall soon skirt the marshy savannahs, 

 between the Upper Orinoco, the Conorichite, and the Cassi- 

 quiare, in the latitude of 3 and 4. There are other open- 

 ings, or as they are called, * clear savannahs,'f in the same 

 parallel, between the sources of the Mao and the Rio de 

 Aguas Blancas, south of the Sierra de Pacaraima. These 

 last savannahs, which are inhabited by Caribs, and nomad 

 Macusis, lie near the frontiers of Dutch and French 

 Guiana. 



Having noticed the geological constitution of South Ame- 

 rica, we shall now mark its principal features. The western 

 coasts are bordered by an enormous wall of mountains, rich 

 in precious metals wherever volcanic fire has not pierced 

 through the eternal snow. This is the Cordillera of the 

 Andes. Summits of trap-porphyry rise beyond three thou- 

 sand three hundred toises, and the mean height of the 

 chain J is one thousand eight hundred and fifty toises. It 

 stretches in the direction of a meridian, and sends into each 

 hemisphere a lateral branch, in the latitudes of 10 north, 

 and 16 and 18 south. The first of these two branches, 

 that of the coast of Caracas, is of considerable length, and 

 forms in fact a chain. The second branch, the Cordillera of 



are covered with snow ; but this colossal group almost belongs to the 

 Andes de la Paz, of which it forms a promontory or spur, directed toward 

 the east. 



* To the west, in consequence of the Llanos of Manso, and the Pampas 

 de Huanacos, the forests do not extend generally beyond the parallels of 

 18 or 19 south latitude; but to the east, in Brazil (in the capitanias of 

 San Pablo and Rio Grande), as well as in Paraguay, on the borders of the 

 Parana, they advance as far as 25 south. 



f Savannas limpias, that is to say, clear of trees. 



t la New Grenada, Quito, and Peru, according to 

 taken by Bouguer, La Condamine, au.d myself. 



