252 GEXEIIAL COUESE OF THE AMAZON. 



pampa and Gruangamarca) by the Nevados of Viuda, Pela- 

 gatos, Moyopata, and Huaylillas, and by the Paramos of 

 (jriiamani and Gruaringa, towards the town of Loxa. The 

 intermedia! chain separates the waters of the Upper Mara- 

 fion from those of the Guallaga, and over a long space 

 reaches only the small elevation of a thousand toises; it 

 enters the region of perpetual snow to the south of 

 Huanuco in the Cordillera of Sasaguanca. It stretches at 

 first northward by Huacrachuco, Chachapoyas, Moyobamba, 

 and the Paramo of Piscoguannuna ; then it progressively 

 lowers toward Peca, Copallin, and the Mission of Santiago, 

 at the eastern extremity of the province of Jaen de Braca- 

 rnoros. The third, or easternmost chain, skirts the right 

 bank of the Bio Gruallaga, and loses itself in the seventh 

 degree of latitude. So long as the Amazon flows froo 

 south to north in the longitudinal valley, between twc 

 chains of unequal height (that is, from the farms of Qui- 

 villa and Gruancaybamba, where the river is crossed on 

 wooden bridges, as far as the confluence of the Rio Chin- 

 chipe), there are neither bars, nor any obstacle whatever to 

 the navigation of boats. The falls of water begin only 

 where the Amazon turns toward the east, crossing the 

 intermedia! chain of the Andes, which widens considerably 

 toward the north. It meets with the first rocks of red 

 sandstone, or ancient conglomerate, between Tambillo and 

 the Pongo of Rentema (near which I measured the breadth, 

 depth, and swiftness of the waters), and it leaves the rocks 

 of red sandstone east of the famous strait of Manseriche, 

 near the Pongo of Tayuchuc, where the hills rise no higher 

 than forty or fifty toises above the level of its waters. The 

 river does not reach the most easterly chain, which bounds 

 the Pampas del Sacramento. From the hills of Tayuchuc 

 as far as Grand Para, during a course of more than seven 

 hundred and fifty leagues, the navigation is free from 

 obstacles. It results from this rapid sketch, that, if the 

 Maranon had not to pass over the hilly country between 

 Santiago and Tomependa (which belongs to the central 

 chain of the Andes) it would be navigable from its mouth 

 as far as Pumpo, near Piscobamba in the province of Con- 

 chucos, forty-three leagues north of its source. 



We have just seen that, in the Orinoco, as in the Amazon, 



