e western edge, and in
harmony with the well-known law that the highest mountains and the
grandest volcanoes face the broadest ocean. The highlands of Brazil and
Guiana have neither volcanic nor snow-clad peaks.[53] Like all the dry
land which first appeared, these primitive mountains on the Atlantic
border trend east and west. The result of this position is a triple
river system--the Orinoco, Amazon, and La Plata, draining three immense
plains--the llanos of Venezuela, the sylvas of Brazil, and the pampas of
the Argentine Republic. The continuity and extent of these vast
depressions are more remarkable even than the height and length of the
mountain chains.[54]

[Footnote 53: "The interior plateau of Brazil (says Dr. Lund) is
composed of horizontal strata of the transition period, which are
nowhere covered with the secondary or tertiary formations." The highest
point in Brazil is 5755 feet. Darwin speaks of "some ancient submarine
volcanic rocks (in the province of La Plata) worth mentioning, from
their rarity on this eastern side of the continent." With the exception
of the coast of Venezuela, the eastern system is little exposed to
earthquakes.]

[Footnote 54: These three plains constitute four fifths of all South
America east of the Andes. The west slope of the Ecuadorian Andes is
about 275 feet per mile; on the east it is 125 feet.]

Such are the characteristic features of South America; they are not
repeated in any other continent.[55] Not one feature could be changed
without destroying those peculiarities of soil and climate which so
remarkably distinguish South America. Its position on the equator places
it in the path of the vapory trade winds, which continually sweep over
it westward till they strike the Andes, which, like a great condenser,
roll a thousand streams eastward again to feed the mighty Amazon. So
effectual is that barrier, not a drop of moisture passes it, and the
trade wind is not felt again on the Pacific till you are one hundred
and fifty miles from the coast. Were the Andes on the Atlantic side,
South America would be turned into a vast Sahara. As it is, the interest
which attaches to this continent, save a few relics of the Incas, is
exclusively that of pure nature. Nowhere does Nature affect us more
deeply with the feeling of her grandeur; nowhere does she exhibit wilder
freaks or more startling contrasts; nowhere do we find such a theatre
for the free development of vegetable and animal