GEOLOGY OF PERU——ADAMS. 391 
The eastern chain extends on the east of Huanta, the convent of 
Ocopa and Tarma, the western chain passes Castrovereyna, Huan- 
cavelica, Huarochari, and Yauli, inclosing a lofty table-land. In 
latitude 10° 11’ the two branches unite in the knot of Huanuco and 
Pasco (Cerro de Pasco). From this point northward the Andes 
divide into three chains. The eastern lies between the Huallaga and 
Pachitea (Ucayali) riv- - 
ers, the second or cen- 
tral between the Hual- 
laga and the Maranon, 
while the third hes be- 
tween the Maranon and 
the coast. The eastern 
range lowers to a range 
of hills, and is lost in 
latitude 6° 15’ on the 
west of Lamas. The 
central, after forming 
the rapids and cataracts 
of the Amazon, turns to 
the northwest and joins 
the knot of Loja in Ecua- 
dor. From the most cer- 
tain information which 
he obtained he concluded 
that to the east of the 
chain which passes to the 
east of Lake Titicaca and 
northward to Huanuco 
a wide mountainous land 
is situated, which is not 
a widening of the east- 
tern chain itself, but 
rather that it consists F!6- 4—Monthly variation of rainfall at Cailloma 
during seven years. 
SEPTEMBER 
OCTOBER 
NOVEMBER 
DECEMBER 
> 
ia 
< 
3 
x 
oO 
ul 
uw 
of heights which  sur- 
round the foot of the Andes like a: penumbra, filling in the whole 
space between the Beni and the Pachitea (Ucayali). 
Humboldt also made interesting comments on the direction of the 
Andes. He noted that in Chile and Upper Peru (Bolivia), from the 
Straits of Magellan to the parallel of Arica (18° 28’ 35’’ S.), the 
whole mass of the Andes runs from south to north in the direction of 
a meridian at the most 5° NE., but from the parallel of Arica the 
coast and the two Cordilleras east and west of the alpine lake of 
Titicaca abruptly change their direction and incline to the northwest. 
88292—sm 1908——26 
