222 
GENERAL COURSE OF THE AMAZON. 
pampa and Guangamarea) by the Novados of Yiuda, Pela- 
gatos, Moyopata, and Huaylillas, and by the Paramos o, 
Guamani and Guaringa, towards the town of Loxa. The 
interinedial chain separates the waters of the Upper Mara- 
bou 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 
Huanueo in the Cordillera of Sasaguanca. It stretches at 
first northward by Tl uacrachueo, Chachapoyas, Moyobaniba, 
and the Paramo of Piscoguanuuna; then it progressively 
lowers toward Peca, Copallin, and the Mission of Santiago, 
at the eastern extremity of the province of .Tarn de Braca- 
rnoros. The third, or easternmost chain, skirts the right 
bank of the Bio Guallaga, and loses itself in the seventh 
degree of latitude. So long as the Amazon flows frotn 
south to north in the longitudinal valley, between twy 
chains of unequal height (that is, from the farms of Qm- 
villa and Guaueaybamba, where the river is crossed on 
wooden bridges, as far as the confluence of the Bio Chiu- 
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 
intermedial chain of the Andes, which widens considerably 
toward the north. It meets with the first rocks of rod 
sandstone, or ancient conglomerate, between Tambillo and 
the Pongo of Kcutema (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 highei 
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 fro® 
obstacles. It results from this rapid sketch, that, if the 
Maraiion had not to pass over the hilly country between 
Santiago and Tomependa (which belongs to the central 
chain of the Andes) it would he navigable from its mouth 
as far as Puinpo, near Piscobamba in the province of Con* 
chueos, forty-three leagues north of its source. 
We have just seen that, in the Orinoco, as in the Amazon, 
