Personal Narrative of Travels to the Equinoctial Regions of America, During the Year 1799-1804 — Volume 3

by Alexander von Humboldt; Aimé Bonpland

The system of the mountains of Parime surpasses in extent nineteen times that of the whole of Switzerland. Even considering the mountainous group of the sources of the Rio Negro and the Xie as independent or insulated amidst the plains, we still find the Sierra Parime (between Maypures and the sources of the Oyapoc) to be 340 leagues in length; its greatest breadth (the rocks of Imataca, near the delta of the Orinoco, at the sources of the Rio Paru) is 140 leagues. In the group of the Parime, as well as in the group of the mountains of central Asia, between the Himalaya and the Altai, the partial chains are often interrupted and have no uniform parallelism. Towards the south-west, however (between the strait of Baraguan, the mouth of the Rio Zama and the Esmeralda), the line of the mountains is generally in the direction of north 70 degrees west. Such is also the position of a distant coast, that of Portuguese, French, Dutch and English Guiana, from Cape North to the mouth of the Orinoco; such is the mean direction of the course of the Rio Negro and Yupura. It is desirable to fix our attention on the angles formed by the partial chains, in different regions of America, with the meridians; because on less extended surfaces, for instance in Germany, we find also this singular co-existence of groups of neighbouring mountains following laws of direction altogether different, though every separate group exhibits the greatest uniformity in the line of chains.

The soil on which the mountains of Parime rise, is slightly convex. By barometric measures I found that, between 3 and 4 degrees north latitude, the plains are elevated from 160 to 180 toises above sea-level. This height will appear considerable if we reflect that at the foot of the Andes of Peru, at Tomependa, 900 leagues from the coast of the Atlantic Ocean, the Llanos or plains of the Amazon rise only to the height of 194 toises. The distinctive characteristics of the group of the mountains of Parime are the rocks of granite and gneiss-granite, the total absence of calcareous secondary formations, and the shelves of bare rock (the tsy of the Chinese deserts), which occupy immense spaces in the savannahs.

5. GROUP OF THE BRAZIL MOUNTAINS.

This group has hitherto been marked on the maps in a very erroneous way. The temperate table-lands and real chains of 300 to 500 toises high have been confounded with countries of exceedingly hot temperature, and of which the undulating surface presents only ranges of hills variously grouped. But the observations of scientific travellers have recently thrown great light on the orography of Portuguese America. The mountainous region of Brazil, of which the mean height rises at least to 400 toises, is comprehended within very narrow limits, nearly between 18 and 28 degrees south latitude; it does not appear to extend, between the provinces of Goyaz and Matogrosso, beyond longitude 53 degrees west of the meridian of Paris.

When we regard in one view the eastern configuration of North and South America, we perceive that the coast of Brazil and Guiana, from Cape Saint Roque to the mouth of the Orinoco (stretching from south-east to north-west), corresponds with that of Labrador, as the coast from Cape Saint Roque to the Rio de la Plata corresponds with that of the United States (stretching from south-west to north-east). The chain of the Alleghenies is opposite to the latter coast, as the principal Cordilleras of Brazil are nearly parallel to the shore of the provinces of Porto Seguro, Rio Janeiro and Rio Grande. The Alleghenies, generally composed of grauwacke and transition rocks, are somewhat loftier than the almost primitive mountains (of granite, gneiss and mica-slate) of the Brazilian group; they are also of a far more simple structure, their chains lying nearer to each other and preserving, as in the Jura, a more uniform parallelism.

If, instead of comparing those parts of the new continent situated north and south of the equator, we confine ourselves to South America, we find on the western and northern coasts in their whole length, a continued chain near the shore (the Andes and the Cordillera of Venezuela), while the eastern coast presents masses of more or less lofty mountains only between the 12 and 30 degrees south latitude. In this space, 360 leagues in length, the system of the Brazil mountains corresponds geologically in form and position with the Andes of Chile and Peru. Its most considerable portion lies between the parallels 15 and 22 degrees, opposite the Andes of Potosi and La Paz, but its mean height is five toises less, and cannot even be compared with that of the mountains of Parime, Jura and Auvergne. The principal direction of the Brazilian chains, where they attain the height of from four to five hundred toises, is from south to north, and from south-south-west to north-north-east; but, between 13 and 19 degrees the chains are considerably enlarged, and at the same time lowered towards the west. Ridges and ranges of hills seem to advance beyond the land-straits which separate the sources of the Rio Araguay, Parana, Topayos, Paraguay, Guapore and Aguapehy, in 63 degrees longitude. As the western widening of the Brazilian group, or rather the undulations of the soil in the Campos Parecis, correspond with the spurs of Santa Cruz de la Sierra, and Beni, which the Andes send out eastward, it was formerly concluded that the system of the mountains of Brazil was linked with that of the Andes of Upper Peru. I myself laboured under this error in my first geologic studies.

A coast chain (Serra do Mar) runs nearly parallel with the coast, north-east of Rio Janeiro, lowering considerably towards Rio Doce, and losing itself almost entirely near Bahia (latitude 12 degrees 58 minutes). According to M. Eschwege* some small ridges reach Cape Saint Roque (latitude 5 degrees 12 minutes). (* Geognostiches Gemulde von Brasilien, 1822. The limestone of Bahia abounds in fossil wood.) South-east of Rio Janeiro the Serra do Mar follows the coast behind the island of Saint Catherine as far as Torres (latitude 29 degrees 20 minutes); it there turns westward and forms an elbow stretching by the Campos of Vacaria towards the banks of the Jacuy.

Another chain is situated westward of the shore-chain of Brazil. This is the most lofty and considerable of all and is called the chain of Villarica. Mr. Eschwege distinguishes it by the name of Serra do Espinhaco and considers it as the principal part of the whole structure of the mountains of Brazil. This Cordillera loses itself northward,* between Minas Novas and the southern extremity of the Capitania of Bahia, in 16 degrees latitude. (* The rocky ridges that form the cataract of Paulo Affonso, in the Rio San Francisco, are supposed to belong to the northern prolongation of the Serra do Espinhaco, as a series of heights in the province of Seara (fetid calcareous rocks containing a quantity of petrified fish) belong to the Serra dos Vertentes.) It is there more than 60 leagues removed from the coast of Porto Seguro; but southward, between the parallels of Rio Janeiro and Saint Paul (latitude 22 to 23 degrees), in the knot of the mountains of Serra da Mantiquiera, it draws so near to the Cordillera of the shore (Serra do Mar), that they are almost confounded together. In the same manner the Serra do Espinhaco follows constantly the direction of a meridian, towards the north; while towards the south it runs south-east, and terminates about 25 degrees latitude. The chain reaches its highest elevation between 18 and 21 degrees; and there the spurs and table-lands at its back are of sufficient extent to furnish lands for cultivation where, at successive heights, there are temperate climates comparable to the delicious climates of Xalapa, Guaduas, Caracas and Caripe. This advantage, which depends at once on the widening of the mass of the chain and of its spurs, is nowhere found in the same degree east of the Andes, not even in chains of more considerable absolute height, as those of Venezuela and the Orinoco. The culminant points of the Serra do Espinhaco, in the Capitania of Minas Geraes, are the Itambe (932 toises), the Serra da Piedade, near Sabara (910 toises), the Itacolumi, properly Itacunumi (900 toises), the Pico of Itabira (816 toises), the Serras of Caraca, Ibitipoca and Papagayo. Saint Hilaire felt piercing cold in the month of November (therefore in summer) in the whole Cordillera of Lapa, from the Villa do Principe to the Morro de Gaspar Suares.

We have just noticed two chains of mountains nearly parallel but of which the most extensive (the littoral chain) is the least lofty. The capital of Brazil is situated at the point where the two chains draw nearest together and are linked together on the east of the Serra de Mantiqueira, if not by a transversal ridge, at least by a mountainous territory. Old systematic ideas respecting the rising of mountains in proportion as we advance into a country, would have warranted the belief that there existed, in the Capitania of Mato Grosso, a central Cordillera much loftier than that of Villarica or do Espinhaco; but we now know (and this is confirmed by climateric circumstances) that there exists no continued chain, properly speaking, westward of Rio San Francisco, on the frontiers of Minas Geraes and Goyaz. We find only a group of mountains, of which the culminant points are the Serras da Canastra (south-west of Paracatu) and da Marcella (latitude 18 1/2 and 19.10 degrees), and, further north, the Pyrenees stretching from east to west (latitude 16 degrees 10 minutes) between Villaboa and Mejaponte). M. Eschwege has named the group of mountains of Goyaz the Serra dos Vertentes, because it divides the waters between the southern tributary streams of the Rio Grande or Parana, and the northern tributary streams of Rio Tucantines. It runs southward beyond the Rio Grande (Parana), and approaches the chain of Espinpapo in 23 degrees latitude, by the Serra do Franca. It attains only the height of 300 or 400 toises, with the exception of some summits north-west of Paracatu, and is consequently much lower than the chain of Villarica.

Further on, west of the meridian of Villaboa, there are only ridges and a series of low hills which, on a length of 12 degrees, form the division of water (latitude 13 to 17 degrees) between the Araguay and the Paranaiba (a tributary of the Parana), between the Rio Topayos and the Paraguay, between the Guapore and the Aguapehy. The Serra of San Marta (longitude 15 1/2 degrees) is somewhat lofty, but maps have vastly exaggerated the height of the Serras or Campos Parecis north of the towns of Cuyaba and Villabella (latitude 13 to 14 degrees, longitude 58 to 62 degrees). These Campos, which take their name from that of a tribe of wild Indians, are vast, barren table-lands, entirely destitute of vegetation; and in them the sources of the tributary streams of three great rivers, the Topayos, the Madeira and the Paraguay, take their rise.