ORIGIN OF THE AMAZON. 
251 
The first, the Attires, is most easily passable -when the 
Waters are low. The Indians prefer crossing the second, 
the Maypures, at the time of great floods. Beyond the 
Haypures and the mouth of the Cano Cameji, the Orinoco 
is again unobstructed for the length of more than one 
hundred and sixty-seven leagues, or nearly to its source; 
that is to say, as far as the Baudalito of Guaharibos, east of 
the Cano Chiguire and the lofty mountains of Tumariquin. 
Having visited the basins of the two rivers Orinoco and 
Amazon, I was singularly struck by the differences they 
display in their course of unequal extent. The falls of the 
Amazon, which is nearly nine hundred and eighty nautical 
leagues (twenty to a degree) in length, arc pretty near .its 
source in the first sixth of its total length, and five-sixths 
°f its course are entirely free. "We find the great falls of 
the Orinoco on a point far more unfavourable to navigation ; 
ji not at the half, at least much beyond the first third of its 
length. In both rivers it is neither the mountains, nor the 
different stages of flat lands lying over one another, whence 
the- 
y take their origin, that cause the 
cataracts ; they are 
after a 
Produced by other mountains, other ledges which, 
°ng and tranquil course, the rivers have to pass over, 
Precipitating themselves from step to step. 
. The Amazon does not pierce its way through the prin- 
? l Pal chain of the Andes, as was affirmed at a period when 
A Was gratuitously supposed that, wherever mountains are 
divided into parallel chains, the intermedia! or central ridge 
r^Ust be more elevated than the others. This great river 
ris es (and this is a point of some importance to geology! 
eastward of the western chain, which alone in this latitude 
Merits the denomination of the high chain of the Andes. 
■ I is formed by the junction of the river Aguamiros with 
. ^ Bio Chavin'illo, which issues from the lake Llauricocha 
.A a longitudinal valley bounded by tbe western and the 
Atermedial chain of the Andes. To form an accurate idea 
„ these hydrographical relations, it must be borne in mind 
at a division into three chains takes place in tbe colossal 
sfoup or ]- n0 (. 0 (- mountains of Pasco and Huanuco. 
op 6 Western chain, which is the loftiest, and takes the name 
j, t! >e Cordillera Real dc Nieve, directs its course (between 
aut T and Caxatamba, Guamachuco and Luema, Micui- 
