Volume Iii Part 12 (2/2)

We have now examined the prolongation of the Sierra Parime on the west, towards the source of the Rio Negro: it remains for us to follow the same group in its eastern direction. The mountains of the Upper Orinoco, eastward of the Raudal of the Guaharibos (north lat.i.tude 1 degree 15 minutes longitude 67 degrees 38 minutes), join the chain of Pacaraina, which divides the waters of the Carony and the Rio Branco, and of which the micaceous schist, resplendent with silvery l.u.s.tre, figures so conspicuously in Raleigh's El Dorado. The part of that chain containing the sources of the Orinoco has not yet been explored; but its prolongation more to the east, between the meridian of the military post of Guirior and the Rupunuri, a tributary of the Essequibo, is known to me through the travels of the Spaniards Antonio Santos and Nicolas Rodriguez, and also by the geodesic labours of two Portuguese, Pontes and Almeida. Two portages but little frequented*

are situated between the Rio Branco and the Rio Essequibo, south of the chain of Pacaraina; they shorten the land-road leading from the Villa del Rio Negro to Dutch Guiana. (* The portages of Sarauru and the lake Amucu.) On the contrary, the portage between the basin of the Rio Branco and that of the Carony crosses the summit of the chain of Pacaraina. On the northern slope of this chain rises the Anocapra, a tributary of the Paraguamusi or Paravamusi; and on the southern slope, the Araicuque, which, with the Uraricapara, forms the famous Valley of Inundations, above the destroyed mission of Santa Rosa (lat.i.tude 3 degrees 46 minutes, longitude 65 degrees 10 minutes). The princ.i.p.al Cordillera, which appears of little breadth, stretches on a length of 80 leagues, from the portage of Anocapra (longitude 65 degrees 35 minutes) to the left bank of the Rupunuri (longitude 61 degrees 50 minutes), following the parallels of 4 degrees 4 minutes and 4 degrees 12 minutes. We there distinguish from west to east the mountains of Pacaraina, Tipique, Tauyana, among which rises the Rio Parime (a tributary of the Uraricuera), Tubachi, Christaux (lat.i.tude 3 degrees 56 minutes, longitude 62 degrees 52 minutes) and Canopiri. The Spanish traveller, Rodriguez, marks the eastern part of the chain by the name of Quimiropaca; but preferring to adopt general names, I continue to give the name of Pacaraina to the whole of this Cordillera which links the mountains of the Orinoco to the interior of Dutch and French Guiana, and which Raleigh and Keymis made known in Europe at the end of the 16th century. This chain is broken by the Rupunuri and the Essequibo, so that one of their tributary streams, the Tavaricuru, takes its rise on the southern declivity, and the other, the Sibarona, on the northern. On approaching the Essequibo, the mountains are more developed towards the south-east, and extend beyond 2 1/2 degrees north lat.i.tude. From this eastern branch of the chain of Pacaraina the Rio Rupunuri rises near the Cerro Ua.s.sari. On the right bank of the Rio Branco, in a still more southern lat.i.tude (between 1 and 2 degrees north) is a mountainous territory in which the Caritamini, the Padaviri, the Cababuri (Cavaburis) and the Pacimoni take their source, from east to west. This western branch of the mountains of Pacaraina separates the basin of Rio Branco from that of the Upper Orinoco, the sources of which are probably not found east of the meridian of 66 15 minutes: it is linked with the mountains of Unturan and Yumariquin, situated south-east of the mission of Esmeralda. Thence it results that, while on the west of the Ca.s.siquiare, between that river, the Atabapo, and the Rio Negro, we find only vast plains, in which rise some little hills and insulated rocks; real spurs stretch eastward of the Ca.s.siquiare, from north-west to south-east, and form a continued mountainous territory as far as 2 degrees north lat.i.tude. The basin only, or rather the transversal valley of the Rio Branco, forms a kind of gulf, a succession of plains and savannahs (campos) several of which penetrate from south to north, into the mountainous land between the eastern and western branches of the chain of Pacaraina, to the distance of eight leagues north of the parallel of San Joaquin.

We have just examined the southern part of the vast system of the mountains of Parime, between 2 and 4 degrees of lat.i.tude, and between the meridians of the sources of the Orinoco and the Essequibo. The development of this system of mountains northward between the chain of Pacaraina and Rio Cuyuni, and between the meridians 66 and 61 3/4 degrees, is still less known. The only road frequented by white men is that of the river Paragua, which receives the Paraguamusi, near the Guirior. We find indeed, in the journal of Nicolas Rodriguez, that he was constantly obliged to have his canoe carried by men (arrastrando) past the cataracts which intercept the navigation; but we must not forget a circ.u.mstance of which my own experience furnished me with frequent proofs--that the cataracts in this part of South America are often caused only by ridges of rocks which do not form mountains.

Rodriguez names but two between Barceloneta and the mission of San Jose; while the missionaries place more to the east, in 6 degrees lat.i.tude, between the Rio Caroni and the Cuyuni, the Serranias of Usupama and Rinocote. The latter crosses the Mazaruni, and forms thirty-nine cataracts in the Essequibo, from the military post of Arinda (lat.i.tude 5 degrees 30 minutes) to the mouth of Rupunuri.

With respect to the continuation of the system of the mountains of Parime, south-east of the meridian of the Essequibo, the materials are entirely wanting for tracing it with precision. The whole interior of Dutch, French and Portuguese Guiana is a terra incognita; and the astronomical geography of those countries has scarcely made any progress during the s.p.a.ce of thirty years. If the American limits recently fixed between France and Portugal should one day cease to be mere diplomatic illusions and acquire reality in being traced on the territory by means of astronomical observations (as was projected in 1817), this undertaking would lead geographical engineers to that unknown region which, at 3 1/2 degrees west of Cayenne, divides the waters between the coast of Guiana and the Amazon. Till that period, which the political state of Brazil seems to r.e.t.a.r.d, the geognostic table of the group of Parime can only be completed by scattered notions collected in the Portuguese and Dutch colonies. In going from the Ua.s.sari mountains (lat.i.tude 2 degrees 25 minutes, longitude 61 degrees 50 minutes) which form a part of the eastern branch of the Cordillera of Pacaraina, we find towards the east a chain of mountains, called by the missionaries Acaray and Tumucuraque. Those two names are found on our maps between 1/2 and 3 degrees north lat.i.tude. Raleigh first made known, in 1596, the system of the mountains of Parime, between the sources of the Rio Carony and the Essequibo, by the name of Wacarima (Pacarima), and the Jesuits Acunha and Artedia furnished, in 1639, the first precise notions of that part of this system which extends from the meridian of Essequibo to that of Oyapoc. There they place the mountains of Yguaracuru and Paraguaxo, the former of which gives birth to a gold river (Rio de oro), a tributary of the Curupatuba;* (* When we know that in Tamanac gold is called caricuri; in Carib, caricura: in Peruvian, cori (curi), we easily recognize in the names of the mountains and rivers (Yguara-curu, Cura-patuba) which we have just marked, the indication of auriferous soil. Such is the a.n.a.logy of the imported roots in the American tongues, which otherwise differ altogether from each other, that 300 leagues west of the mountain Ygaracuru, on the banks of the Caqueta, Pedro de Ursua heard of the province of Caricuri, rich in gold was.h.i.+ngs. The Curupatuba falls into the Amazon near the Villa of Monte Alegre, north-east of the mouth of the Rio Topayos.); and according to the a.s.sertion of the natives, subterraneous noises are sometimes heard from the latter. The ridge of this chain of mountains, which runs in a direction south 85 degrees east from the peak of Duida near the Esmeralda (lat.i.tude 3 degrees 19 minutes), to the rapids of the Rio Manaye near Cape Nord (lat.i.tude 1 degree 50 minutes), divides, in the parallel of 2 degrees, the northern sources of the Essequibo, the Maroni and the Oyapoc, from the southern sources of the Rio Trombetas, Curupatuba and Paru. The most southern spurs of this chain approach nearer to the Amazon, at the distance of fifteen leagues.

These are the first heights which we perceived after having left Xeberos and the mouth of the Huallaga. They are constantly seen in navigating from the mouth of the Rio Topayo towards that of Paru, from the town of Santarem to Almeirim. The peak Tripoupou is nearly in the meridian of the former of those towns and is celebrated among the Indians of Upper Maroni. It is said that farther eastward, at Melgaco, the Serras do Velho and do Paru are still distinguished in the horizon. The real boundaries of this series of sources of the Rio Trombetas are better known southward than northward, where a mountainous country appears to advance in Dutch and French Guiana, as far as within twenty to twenty-five leagues of the coast. The numerous cataracts of the rivers of Surinam, Maroni and Oyapoc, prove the extent and the prolongation of rocky ridges; but in those regions nothing indicates the existence of continued plains or table-lands some hundred toises high, fitted for the cultivation of the plants of the temperate zone.

The system of the mountains of Parime surpa.s.ses 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 lat.i.tude, 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 s.p.a.ces in the savannahs.

5. GROUP OF THE BRAZIL MOUNTAINS.

This group has. .h.i.therto 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 lat.i.tude; 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 princ.i.p.al Cordilleras of Brazil are nearly parallel to the sh.o.r.e 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 sh.o.r.e (the Andes and the Cordillera of Venezuela), while the eastern coast presents ma.s.ses of more or less lofty mountains only between the 12 and 30 degrees south lat.i.tude. In this s.p.a.ce, 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 princ.i.p.al 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 (lat.i.tude 12 degrees 58 minutes). According to M. Eschwege* some small ridges reach Cape Saint Roque (lat.i.tude 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 (lat.i.tude 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 sh.o.r.e-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 princ.i.p.al 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 lat.i.tude. (* 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 quant.i.ty 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 (lat.i.tude 22 to 23 degrees), in the knot of the mountains of Serra da Mantiquiera, it draws so near to the Cordillera of the sh.o.r.e (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 lat.i.tude. 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 ma.s.s 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 circ.u.mstances) 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 (lat.i.tude 18 1/2 and 19.10 degrees), and, further north, the Pyrenees stretching from east to west (lat.i.tude 16 degrees 10 minutes) between Villaboa and Mej.a.ponte). 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 lat.i.tude, 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 (lat.i.tude 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 (lat.i.tude 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 dest.i.tute 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.

According to the measures and geologic observations of M. Eschwege, the high summits of the Serra do Mar (the coast-chain) scarcely attain 660 toises; those of the Serra do Espinhaco (chain of Villarica), 950 toises; those of Serra de los Vertentes (group of Canastra and the Brazilian Pyrenees), 450 toises. Further west the surface of the soil seems to present but slight undulations; but no measure of height has been made beyond the meridian of Villaboa. Considering the system of the mountains of Brazil in their real limits, we find, except some conglomerates, the same absence of secondary formations as in the system of the mountains of the Orinoco (group of Parime). These secondary formations, which rise to considerable heights in the Cordillera of Venezuela and c.u.mana, belong only to the low regions of Brazil.

B. PLAINS (LLANOS) OR BASINS.

In that part of South America situated on the east of the Andes we have successively examined three systems of mountains, those of the sh.o.r.e of Venezuela, of the Parime and Brazil: we have seen that this mountainous region, which equals the Cordillera of the Andes, not in ma.s.s, but in area and horizontal section of surface, is three times less elevated, much less rich in precious metals adhering to the rock, dest.i.tute of recent traces of volcanic fire and, with the exception of the coast of Venezuela, little exposed to the violence of earthquakes.

The average height of the three systems diminishes from north to south, from 750 to 400 toises; those of the culminant points (maxima of the height of each group) from 1350 to 1000 or 900 toises. Hence it results that the loftiest chain, with the exception of the small insulated system of the Sierra Nevada of Santa Marta, is the Cordillera of the sh.o.r.e of Venezuela, which is itself but a continuation of the Andes. Directing our attention northward, we find in Central America (lat.i.tude 12 to 30 degrees) and North America (lat.i.tude 30 to 70 degrees), on the east of the Andes of Guatimala, Mexico and Upper Louisiana, the same regular lowering which struck us towards the south. In this vast extent of land, from the Cordillera of Venezuela to the polar circle, eastern America presents two distinct systems, the group of the mountains of the West Indies (which in its eastern part is volcanic) and the chain of the Alleghenies. The former of these systems, partly covered by the ocean, may be compared, with respect to its relative position and form, to the Sierra Parime; the latter, to the Brazil chains, running also from south-west to north-east. The culminant points of those two systems rise to 1138 and 1040 toises. Such are the elements of this curve, of which the convex summit is in the littoral chain of Venezuela:

AMERICA, EAST OF THE ANDES.

COLUMN 1 : SYSTEMS OF MOUNTAINS.

COLUMN 2 : MAXIMA OF HEIGHTS IN TOISES.

Brazil Group : Itacolumi 900 (south lat.i.tude 20 1/2 degrees).

Parime Group : Duida 1300 (north lat.i.tude 3 1/4 degrees).

Littoral Chain of Venezuela : Silla of Caracas 1350 (north lat.i.tude 10 1/2 degrees).

Group of the West Indies : Blue Mountains 1138 (north lat.i.tude 18 1/5 degrees).

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