461 



! Among the basins which the sketch of the 

 Andes presents, and which form probably as 

 many lakes or small interior seas, the basins of 

 Titicaca, Rio Jauja, and the Upper Maragnon, 

 have respectively 3500, 1300, and 2400 square 

 leagues of surface *. The first is so inclosed, that 

 no drop of water can escape except by evapora- 

 tion ; it is a repetition of the shut up valley of 

 Mexico-^, and of those numerous circular basins 

 which are discovered in the moon, and are sur- 



* I shall state in this note the whole of those estimates 

 which interest geologists. Area of the Andes, from the 

 Land of Fire to the Paramo of las Rosas (lat. 9|° nor.), 

 where the mountainous land of Tocuyo and Barquesimeto 

 begins, part of the Cordillera of the shore of Venezuela, 

 58,900 square leagues, 20 to a degree ; the four counter- 

 forts of Cordova, Salta, Cochabamba, and Beni alone, occupy 

 23,300 square leagues of this surface, and the three basins 

 contained between the 6° and 20° of south latitude, 7200 

 square leagues. Deducting 33,200 square leagues for the 

 whole of the inclosed basins and counterforts, we find in 65° 

 of latitude, the area of the Cordilleras elevated in the form 

 of walls, to be 25,700 square leagues, whence results 

 (comprehending the knots, and admitting the inflexion of the 

 chains,) a mean breadth of the Andes of 18 to 20 leagues. 

 (See above, p. 409.) The valleys of Huallaga and the Rio 

 Magdalena are not comprehended in these 58,900 square 

 leagues, on account of the diverging direction of the chain, 

 east of Chicoplaya and Santa Fe de Bogota. 



f We consider it in its primitive state, without respect to 

 the trench or cleft of the mountains, known by the name of 

 Desague de Huehuetoca. 



