456 



parallel, and sometimes articulated by immense 

 knots of mountains* We distinguish nine of 

 those knots, and consequently an equal num- 

 ber of branching points and ramifications. The 

 latter are generally bifurcations : the Andes are 

 twice only divided into three chains, in the knot 

 of Huanuco, near the source of the Amazon, 

 and the Huallaga, (lat. 10° to 11°,) and in the 

 knot of the Paramo de las Papas (lat. 2°), near 

 the source of the Magdalena and the Cauca. Ba- 

 sins, almost shut in at their extremities, parallel 

 to the axis of the Cordillera, and bounded by 

 two knots and two lateral chains, are charac- 

 teristic features of the structure of the Andes. 

 Among these knots of mountains, some, for in- 

 stance those of Cuzco, Loxa, and Los Pastos, 

 are 3300, 1500, and 1130 square leagues, while 

 others no less important in the eyes of the 

 geologist are restrained to ridges or trans- 

 versal dykes. To the latter belong the Altos 

 de Chisinche (lat. 0° 40' south), and the Los 

 Robles (lat. 2° 20' north), on the south of Quito 

 and Popayan. The knot of Couzco, so cele- 

 brated in the annals of Peruvian civilization, pre- 

 sents a mean height of from 1200 to 1400 toises, 

 and a surface nearly three times greater than the 

 whole of Switzerland. The ridge of Chisinche, 

 which separates the basins of Tacunga and 

 Quito, is 1580 toises of absolute height, but 

 scarcely a mile broad. The knots or groupes 



