The Andes and the Amazon Part 6

[Footnote 52: On this point see Chapter XVII.]

In South America Nature has framed her works on a gigantic scale. Where else combined do we see such a series of towering mountains, such a volume of river-water, and such wide-spreading plains? We have no proper conception of Andine grandeur till we learn that the top of the tallest mountain in North America is nearly a mile beneath the untrodden dome of Chimborazo; nor any just view of the vast dimensions of the Amazonian Valley till we find that all the United States could be packed in it without touching its boundaries; nor any adequate idea of the Amazon itself till we ascertain that it drains a million square miles more than the Mississippi.

South America is a triangular continent, with its axis, the Andes, not central, as in Europe, but lying on its extreme 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 const.i.tute 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 pa.s.ses 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 life.

[Footnote 55: There is, however, a striking coincidence between the mountain and river systems of the northern and southern continents of this hemisphere. Thus,

The Andes represent the Rocky Mountains, " Highland of Guiana represent the Canadian Mountains.

" " Brazil " Appalachian "

" Amazon " Saskatchewan.

" La Plata " Mississippi.

" Orinoco " Mackenzie.

The long and lofty chain of the Andes is certainly one of the grandest results of the plications and uplifts of the earth's crust. While the waves of the Pacific, from Panama to Patagonia, submissively kiss the feet of the Andes, and the showers that swell the Amazon fall within sight of the mariner on that peaceful ocean, the Rocky Mountains are situated five hundred miles from the sea. The s.p.a.ce west of the Andes does not contain 20,000 square leagues, while the country east of it equals 424,600. While the compact Andes have an average width of only sixty miles,[56] the straggling mountain system beyond the Mississippi has the breadth of the Empire State; but the mean elevation of the latter would scarcely reach the bottom of the Quito Valley. The mountains of Asia may surpa.s.s the Cordilleras in height, but, situated beyond the tropics, and dest.i.tute of volcanoes, they do not present that inexhaustible variety of phenomena which characterizes the latter. The outbursts of porphyry and trachytic domes, so characteristic of the high crests of the Cordilleras, impart a physiognomy quite distinct from that presented by the mountains of Europe. The Andes offer, in the least s.p.a.ce, the greatest possible variety of impressions.[57] There is near Huanca, Peru, a coal-bed lifted up to the enormous height of 14,700 feet, and on the side of Chimborazo there is a salt spring 13,000 feet above the sea. Marine sh.e.l.ls have not been found in Europe above the summit of the Pyrenees, or 11,700 feet; but the Andes can show some a thousand feet higher. A strange sight, to see sh.e.l.ls once crawling on the bottom of the ocean now resting at an elevation twice the height of Mount Washington!

[Footnote 56: The width of the chain south of the equator varies with that of the continent.]

[Footnote 57: "No mountains which I have seen in Hungary, Saxony, or the Pyrenees are as irregular as the Andes, or broken into such alternate substances, manifesting such prodigious revolutions of nature."--_Helms_.

"More sublime than the Alps by their _ensemble_, the Andes lack those curious and charming details of which Nature has been so lavish in the old continent."--_Holinski_.]

Beneath the Southern Cross, out of a sea perpetually swept by fearful gales, rise the rocky hills of Terra del Fuego. It is the starting-point of that granite chain which winds around the earth in a majestic curve, first northwesterly to the Arctic Sea, thence by the Aleutian and j.a.panese Isles to Asia, crossing the Old World southwesterly from China to South Africa.

Skirting the bleak sh.o.r.es of Patagonia in a single narrow sierra, the Andes enter Chile, rising higher and higher till they culminate in the gigantic porphyritic peak of Aconcagua. At the boundary-line of Bolivia, the chain, which has so far followed a precise meridional direction, turns to the northwest, and, at the same time, separates into two Cordilleras, inclosing the great table-land of Desaguadero. This wonderful valley, the Thibet of the New World, has four times the area of New York State, and five times the elevation of the Catskill Mountain House. At one end of the valley, perched above the clouds, is silvery Potosi, the highest city in the world; at the other stands the once golden capital of Cuzco. Between them is Lake t.i.ticaca[58] (probably an ancient crater), within which is an island celebrated as the cradle of the strange empire of Peru, which, though crushed by Pizarro in its budding civilization, ranks as the most extraordinary and extensive empire in the annals of American history. The Cordillera, of which Sahama, Sorata, and Illimani are the pinnacles, so completely inclose this high valley that not a drop of water can escape except by evaporation. At the silver mines of Pasco the Andes throw off a third cordillera, and with this triple arrangement and a lower alt.i.tude, enter the republic of Ecuador. There they resume the double line, and surpa.s.s their former magnificence. Twenty volcanoes, presided over by the princely Chimborazo and Cotopaxi, rise out of a sublime congregation of mountains surrounding the famous valley of Quito. In New Granada there is a final and unique display of Andine grandeur: the Cordilleras combine just above the equator into one dizzy ridge, and then spread out like a fan, or, rather, like the graceful branches of the palm. One sierra bends to the east, holding in its lap the city of Bogota, and, rolling off a thousand streams to swell the Orinoco, terminates in the beautiful mountains of Caracas; the central range culminates in the volcanic Tolima,[59] but is soon lost in the Caribbean Sea; the western chain turns to the left, humbling itself as it threads the narrow isthmus, and expands into the level table-land of Mexico. You may cross Mexico from ocean to ocean in a carriage, but no wheeled vehicle ever crossed South America.

[Footnote 58: This lake is the largest fresh-water acc.u.mulation in South America. It has diminished within the historic period. Its surface is 12,795 feet above the Pacific, or higher than the highest peaks of the Pyrenees.]

[Footnote 59: This is the loftiest summit of the Andes in the northern hemisphere, being 18,200 feet. It is also remarkable for being situated farther from the sea (120 miles) than any other active volcano.]

[Ill.u.s.tration: Profiles of Ecuadorian Volcanoes

10,000 ft. Chimborazo.

10,000 ft. Cotopaxi.

10,000 ft. Caraguairazo.

10,000 ft. Pichincha.

We will now speak more particularly of the Andes of the equator. The mountain chain is built up of granite, gneissoid, and schistose rocks, often in vertical position, and capped with trachyte and porphyry.[60]

Large ma.s.ses of _solid_ rock are rarely seen; every thing is cracked, calcined, or triturated. While in Bolivia the Eastern Cordillera shows a succession of sharp, ragged peaks, in contrast with the conical summits of the Cordillera of the coast, there is no such distinction in the Andes of the equator.[61] The Eastern Cordillera has a greater mean height, and it displays more volcanic activity. Twenty volcanic mountains surround the valley, of which twelve are in the oriental chain. Three of the twenty are now active (Cotopaxi, Sangai, and Pichincha), and five others are known to have erupted since the Conquest (Chiles, Imbabura, Guamani, Tunguragua, and Quirotoa). The truncated cone of Cotopaxi, the jagged, Alpine crest of ruined Altar, and the dome of Chimborazo, are the representative forms of the volcanic summits. The extinct volcanoes usually have double domes or peaks, while the active peaks are slender cones. Antisana and Cayambi are fashioned after Chimborazo, though the latter is table-topped rather than convex; Caraguairazo, Quirotoa, Iliniza, Sincholagua, Ruminagui, and Corazon, resemble Altar; Tunguragua, Sangai, Llanganati, Cotocachi, Chiles, and Imbabura, imitate Cotopaxi; Pichincha, Atacatzo, and Guamani are irregular. The Ecuadorian volcanoes have rarely ejected liquid lava, but chiefly water, mud, ashes, and fragments of trachyte and porphyry.

Cotopaxi alone produces pure, foam-like pumice, and glossy, translucent obsidian.[62] The paucity of quartz, and the absence of basalt, are remarkable. Some of the porphyroids are conglomerate, but the majority are true porphyries, having a h.o.m.ogeneous base. Dr. T.

Sterry Hunt calls them porphyroid trachytes. They have a black, rarely reddish, vitreous, or impalpable base, approaching obsidian, with a specific gravity of 2.59 in pure specimens, and holding crystals or crystalline grains of gla.s.sy feldspar, and sometimes of pyroxene and hemat.i.te. They differ from the Old World porphyries in containing no quartz, and seldom mica.[63] D'Orbigny considers the porphyries of the Andes to have been ejected at the close of the cretaceous period, and formed the first relief of the Cordillera. The prevalence of trachyte shows that the products have cooled under feeble pressure.

[Footnote 60: "As a general rule, whenever the ma.s.s of mountains rises much above the limit of perpetual snow, the primitive rocks disappear, and the summits are trachyte or trappean porphyry."--_Humboldt_. In general, "the great Cordilleras are formed of innumerable varieties of granites, gneiss, schists, hornblende, chloritic slates, porphyries, etc., and these rocks alternate with each other in meridional bands, which in the ridges frequently present the appearance of a radiated or fan-shaped structure, and under the plains are more or less vertical."--_Evan Hopkins, F.G.S_.]

[Footnote 61: Von Tschudi makes the incorrect statement that "throughout the whole extent of South America there is not a single instance of the Western Cordillera being intersected by a river." Witness the Esmeraldas.]

[Footnote 62: It is a singular fact that true trachyte, pumice, and obsidian are wanting in the volcanic Galapagos Islands, only 700 miles west of Pichincha.]

[Footnote 63: As many of the crystals are partly fused, or have round angles, the porphyries were probably formed by the melting of a crystalline rock, the base becoming fused into a h.o.m.ogeneous material, while the less fusible crystals remain imbedded.--_Dr. Hunt_.]

From the deluges of water lately thrown out have resulted deep furrows in the sides; and from the prevalence of the east wind, which is always met by the traveler on the crest of either Cordillera, there is a greater acc.u.mulation of ashes, and less snow on the west slope. Cotopaxi is a fine example of this. In Pichincha, Altar, and Ruminagua, however, the western wall is lowest, apparently broken down.[64] There is no synchronism in the eruptions of Cotopaxi and Pichincha. These volcanoes must have independent reservoirs, for the former is 3000 feet higher than the latter, and only thirty miles distant. The reputed eruptions of Pichincha are dated 1534, 1539, 1566, 1575, 1588, and 1660; that of 1534 resting on the a.s.sertions of Checa, Garcilazo, and Herrera, indorsed by Humboldt. Excepting the traditional eruption in 1534, which probably is confounded with that of Pichincha, Cotopaxi did not open till 1742; then followed the eruptions of 1743, 1744, 1746, 1766, 1768, 1803, 1851, and 1855. We must mention, however, that, since the recent awakening of Pichincha, Cotopaxi has been unusually silent. There is also a remarkable coincidence (which may not be wholly accidental) in the renewed activity of Pichincha, and the great eruption of Mauna Loa, both occurring in March, 1868. It is generally believed by the natives that Cotopaxi and Tunguragua are sympathetic.

[Footnote 64: In the Galapagos volcanoes the south wall is lowest, while the craters in Mexico and Sandwich Islands are lowest on the northeast.]

There are fifty-one volcanoes in the Andean chain. Of these, twenty girdle the Valley of Quito, three active, five dormant, and twelve extinct.[65] Besides these are numerous mountain peaks not properly volcanic. Nowhere on the face of the earth is there such a grand a.s.semblage of mountains. Twenty-two summits are covered with perpetual snow, and fifty are over ten thousand feet high.[66]

[Footnote 65: The alt.i.tudes of the most important Ecuadorian volcanoes are:

WESTERN CHAIN.

_Chimborazo_, 21,420 feet (Humboldt).

_Caraguairazo_, 19,183 feet (Humboldt).

It is variously estimated from 15,673 feet to 19,720 feet; 18,000 feet is not far from the truth.

_Iliniza_, 17,370 feet (Wisse); 16,300 (Hall).

_Cotocachi_, 16,440 feet (Humboldt); 16,409 (Wisse).

_Pichincha_, 15,922 feet (Humboldt); 15,827 (Orton).

EASTERN CHAIN.

_Cayambi_, 19,648 feet (Humboldt); 19,358 (Wisse).

_Antisana_, 19,148 feet (Humboldt); 19,279 (Wisse).

_Cotopaxi_, 18,880 feet (Humboldt); 18,862 (Wisse).

_Altar_, 17,400 feet.

_Sangai_, 17,120 feet (Wisse).

_Tunguragua_, 16,579 feet (Humboldt).

_Sincholagua_, 16,434 feet (Humboldt).

[Footnote 66: The snow limit at the equator is 15,800 feet. No living creature, save the condor, pa.s.ses this limit; naked rocks, fogs, and eternal snows mark the reign of uninterrupted solitude. The following is the approximate limit of perpetual snow in different lat.i.tudes:

0 15,800 feet.

27 18,800 "

33 12,780 "

40 8,300 feet.

54 3,700 "

70 3,300 "

The limit appears to descend more rapidly going south of the equator than in going north.]