■WESTEUIf CHAIN OF THE ANUES. 
303 
10’ and 5®, no summit of tlie eastern and central chains rises 
as hi(^li as’ the region of perpetual snow; the onl_v snowy 
summits are in the western chain. The central chain, tliat 
of the Paramos de Callacalla, and Piscoguanuna, scarcely 
attains 1800 toises, and lowers gently to 800 toises; so timt 
the mountainous and temperate tract of country which 
extends on the north of Chachapoyas towards Pomacocha, 
La Vellaca, and the source of the Pio Nieva, is rich in fine 
cinchona trees. After having jmssed the Pio Piiallaga and 
the Pachitea, ivhich with the Beni forms the Ucayali, we 
find, in advancing towards the east, only ranges of lulls. 
The western chain of the Andes, which is the most elevated 
and nearest to the coast, runs almost parallel nuth the shore 
]Sr 900 ^ between Caxatambo and Huary, Conchucos and 
Guamachu’co, by Caxamarca, the Paramo de Yanagiianga, 
and Montan, towards the Rio de Guancabamba. It comprises 
(between 9° and 7^“) the three Nevados de Pelagatos, hloyo- 
pata and ITiiaylillas. This last snowy summit, situated near 
Giia’machuco, (in 7° 55' lat.) is the more remarkable since 
from thence on the north, as far as Chimborazo, on a length 
of 110 leagues, there is not one mountain that enters the 
region of perpetual snow. This depression, or absence of 
snow, extends in the same interval, over all the lateral chains ; 
while, on the south of the Nevado de Huaylillas, it alwavs 
happens that when one chain is very low, the summits ot the 
other exceed the height of 24G0 toises. It was on the south 
of Micuipampa (lat. 7" 1') that I found the magnetic equator. 
The ^Vmazon, or as it is customary to say in those 
regions, the Upper Marafion, flows through the western part 
of the longitudinal valley lying between the Cordilleras ot 
Chachapavas and Oaxamarca. Comprehending m one point 
of view, tills vallev, and that of the Pio Jaiija, bounded by 
the Coi-dilleras of Tarma and Huarocheri, we are mchned to 
consider them as one immense basin 180 leagues long, ana 
crossed in the first third of its length, by a dyke, or ridge 
18,000 toises broad. In fact, the tu'o alpine lakes ot Laun- 
cocha and Chinchaycocha, where the river Amazon and the 
Rio de Jauia take their rise, are situated south and north ot 
this rocky dyke, which is a prolongation of the kno o 
Huanuco ana Pasco. The Amazon, on issuing from the 
longitudinal valley whicli bounds tlie cliams oi Caxamarca 
