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Amazon River

The Amazon River is the greatest river on Earth. Before the conquest of South America, the Rio de las Amazonas had no general name; for, according to a common custom, each Indian tribe gave a name only to the section of the river which it occupied -- such as Paranaguazu, Guyerma, Solimões and others. In the year 1500, Vicente Yañez Pinzon, in command of a Spanish expedition, became the first European to explore the river and ascended the Amazon to a point about 50 meters from the sea. He called it the Rio Santa Maria de la Mar Dulce, which soon became abbreviated to Mar Dulce, and for some years, after 1502, it was known as the Rio Grande. The principal companions of Pinzon, in giving evidence in 1513, mention it as El Ryo Haranon. There is much controversy about the origin of the word Maranon. Peter Martyr in a letter to Lope Hurtado de Mendoza in 1513 is the first to state that it is of native origin. Ten years after the death of Pinzon, his friend Oviedo calls it the Marañón. Many writers believe that this was its Indian name. We are disposed to agree with the Brazilian historian Constancio that Marañón is derived from the Spanish word maraña, a tangle, a snarl, which well represents the bewildering difficulties which the earlier explorers met in navigating not only the entrance to the Amazon, but the whole island-bordered, river-cut and indented coast of the now Brazilian province of Maranhão.

The first descent by a European of the mighty artery from the Andes to the sea was made by Orellana in 1541, and the name Amazonas arises from the battle which he had with a tribe of Tapuya savages where the women of the tribe fought alongside the men, as was the custom among all of the Tapuyas. Orellana, no doubt, derived the name Amazonas from the ancient Amazons of Asia and Africa described by Herodotus and Diodorus.

The first ascent by a European of the river was made in 1638 by Pedro Texiera, a Portuguese, who reversed the route of Orellana and reached Quito by way of the Rio Napo. He returned in 1639 with the Jesuit fathers Acuna and Artieda, delegated by the viceroy of Peru to accompany him.

The river Amazon has a drainage area of 7,050,000 km2 (2,722,000 square miles), if the Tocantins River is included in its basin. It drains four-tenths of South America, and it gathers its waters from 5 degrees northern to 20 degrees southern latitude. Its most remote sources are found on the inter-Andean plateau, but a short distance from the Pacific Ocean; and, after a course of about 7200 km (4800 miles) through the interior of Peru and across Brazil, it enters the Atlantic Ocean on the equator. It is generally accepted by geographers that the Marañón, or Upper Amazon, rises in the little lake, Lauricocha, in 10 degrees 30' southern latitude, and 160 km (100 miles) N.N.E. of Lima. They appear to have followed the account given by Padre Fritz which has since been found incorrect. According to Antonio Raimondi, it is the Rio de Nupe branch of the small stream which issues from the lake that has the longer course and the greater volume of water. The Nupe rises in the Cordillera de Huayhuath and is the true source of the Marañón. There is a difference among geographers as to where the Marañón ends and the Amazon begins, or whether both names apply to the same river. The Pongo de Manseriche [note 1], at the base of the Andes and the head of useful navigation, seems to be the natural terminus of the Marañón; and an examination of the hydrographic conditions of the great valley makes the convenience and accuracy of this apparent. Raimondi terminates the Maranon at the mouth of the Ucayali, Reclus the same, both following the missionary fathers of the colonial period. C. M. de la Condamine uses "Amazon" and "Marañón" indiscriminately and considers them one and the same. Smyth and Lowe give the mouth of the Javary as the eastern limit, as does d'Orbigny. Wolf, apparently uncertain, carries the "Marañón or Amazon" to the Peruvian frontier of Brazil at Tabatinga. Other travellers and explorers contribute to the confusion. This probably arises from the rivalry of the Spaniards and Portuguese. The former accepted the name Marañón in Peru, and as the missionaries penetrated the valley they extended the name until they reached the mouth of the Ucayali; while, as the Portuguese ascended the Amazon, they carried this name to the extent of their explorations. Beginning with the lower river we propose to notice, first, the great affluents which go to swell the volume of the main stream.

Table of contents
1 Tributaries
2 The Main River
3 External links

Tributaries

The Main River

Physical characteristics

The Amazon main river is navigable for ocean steamers as far as Iquitos, 2300 miles from the sea, and 486 miles higher up for vessels drawing 14 ft. of water, as far as Achual Point. Beyond that, according to Tucker, confirmed by Wertheman, it is unsafe; but small steamers frequently ascend to the Pongo de Manseriche, just above Achual Point The average current of the Amazon is about 3 miles an hour; but, especially in flood, it dashes through some of its contracted channels at the rate of 5 mph. The U.S. steamer Wilmington ascended it to Iquitos in 1899. Commander Todd reports that the average depth of the river in the height of the rainy season is 120 ft. It commences to rise in November, and increases in volume until June, and then falls until the end of October. The rise of the Negro branch is not synchronous; for the steady rains do not commence in its valley until February or March. By June it is full, and then it begins to fall with the Amazon. According to Bates, the Madeira "rises and sinks" two months earlier than the Amazon. The Amazon at times broadens to 4 and 6 miles. Occasionally, for long distances, it divides into two main streams with inland, lateral channels, all connected by a complicated system of natural canals, cutting the low, flat igapo lands, which are never more than 15 ft. above low river, into almost numberless islands. [Note 3] At the narrows of Obidos, 400 miles from the sea, it is compressed into a single bed a mile wide and over 200 ft. deep, through which the water rushes at the rate of 4 to 5 miles an hour. In the rainy season it inundates the country throughout its course to the extent of several hundred thousand square miles, covering the flood-plain, called vargem. The flood-levels are in places from 40 to 50 ft. high above low river. Taking four roughly equidistant places, the rise at Iquitos is 20 ft., at Teffe 45, near Obidos 35, and at Para 12 ft.

The first high land met in ascending the river is on the north bank, opposite the mouth of the Xingu, and extends for about 150 miles up, as far as Monte Alegre. It is a series of steep, table-topped hills, cut down to a kind of terrace which lies between them and the river. Monte Alegre reaches an altitude of several hundred feet. On the south side, above the Xingu, a line of low bluffs extends, in a series of gentle curves with hardly any breaks nearly to Santarem, but a considerable distance inland, bordering the flood-plain, which is many miles wide. Then they bend to the south-west, and, abutting upon the lower Tapajos, merge into the bluffs which form the terrace margin of that river valley. The next high land on the north side is Obidos, a bluff, 56 ft. above the river, backed by low hills. From Serpa, nearly opposite the river Madeira, to near the mouth of the Rio Negro, the banks are low, until approaching Manaos, they are rolling hills; but from the Negro, for 600 miles as far up as the village of Canaria, at the great bend of the Amazon, only very low land is found, resembling that at the mouth of the river. Vast areas of it are submerged at high water, above which only the upper part of the trees of the sombre forests appear. At Canaria, the high land commences and continues as far as Tabatinga, and thence up stream.

On the south side, from the Tapajos to the river Madeira, the banks are usually low, although two or three hills break the general monotony. From the latter river, however, to the Ucayali, a distance of nearly 1500 miles, the forested banks are just out of water, and are inundated long before the river attains its maximum flood-line. Thence to the Huallaga the elevation of the land is somewhat greater; but not until this river is passed, and the Pongo de Manseriche approached, does the swelling ground of the Andean foot-hills raise the country above flood-level.

The Amazon is not a continuous incline, but probably consists of long, level stretches connected by short inclined planes of extremely little fall, sufficient, however, owing to its great depth, to give the gigantic volume of water a continuous impulse towards the ocean. The lower Amazon presents every evidence of having once been an ocean gulf, the upper waters of which washed the cliffs near Obidos. Only about 10% of the water discharged by the mighty stream enters it below Obidos, very little of which is from the northern slope of the valley. The drainage area of the Amazon basin above Obidos is about 1,945,000 sq. miles, and, below, only about 423,000 sq. miles., or say 20%, exclusive of the 554,000 sq. miles of the Tocantins basin.

The width of the mouth of the monarch river is usually measured from Cabo do Norte to Punto Patijoca, a distance of 207 statute miles; but this includes the ocean outlet, 40 miles wide, of the Para river, which should be deducted, as this stream is only the lower reach of the Tocantins. It also includes the ocean frontage of Marajo, an island about the size of the kingdom of Denmark lying in the mouth of the Amazon.

Following the coast, a little to the north of Cabo do Norte, and for 100 miles along its Guiana margin up the Amazon, is a belt of half-submerged islands and shallow sandbanks. Here the tidal phenomenon called the bore, or Pororoca, occurs, where the soundings are not over 4 fathoms. It commences with a roar, constantly increasing, and advances at the rate of from 10 to 15 miles an hour, with a breaking wall of water from 5 to 12 ft. high. Under such conditions of warfare between the ocean and the river, it is not surprising that the former is rapidly eating away the coast and that the vast volume of silt carried by the Amazon finds it impossible to build up a delta.

The Amazon is not so much a river as it is a gigantic reservoir, extending from the sea to the base of the Andes, and, in the wet season, varying in width from 5 to 400 m. Special attention has already been called to the fourteen great streams which discharge into this reservoir, but it receives a multitude of secondary rivers, which in any other part of the world would also be termed great.

Population, trade, etc.

For 350 years after the European discovery of the Amazon, by Pinzon, the Portuguese portion of its basin remained almost an undisturbed wilderness, occupied by Indian tribes whom the food quest had split into countless fragments. It is doubtful if its indigenous inhabitants ever exceeded one to every 5 sq. miles of territory, this being the maximum it could support under the existing conditions of the period in question, and taking into account Indian methods of life. A few settlements on the banks of the main river and some of its tributaries, either for trade with the Indians or for evangelizing purposes, had been founded by the Portuguese pioneers of European civilization. The total population of the Brazilian portion of the Amazon basin in 1850 was perhaps 300,000, of whom about two-thirds were white and slaves, the latter numbering about 25,000. The principal commercial city, Para, had from 10,000 to 12,000 inhabitants, including slaves. The town of Manaos, at the mouth of the Rio Negro, had from 1000 to 1500 population; but all the remaining villages, as far up as Tabatinga, on the Brazilian frontier of Peru, were wretched little groups of houses which appeared to have timidly effected a lodgment on the river bank, as if they feared to challenge the mysteries of the sombre and gigantic forests behind them. The value of the export and import trade of the whole valley in 1850 was but

On the 6th of September 1850 the emperor, Dom Pedro II, sanctioned a law authorizing steam navigation on the Amazon, and confided to an illustrious Brazilian, Barao Maua (Irineu Evangilista de Sousa), the task of carrying it into effect. He organized the "Compania de Navigacao e Commercio do Amazonas" at Rio de Janeiro in 1852; and in the following year it commenced operations with three small steamers, the "Monarch," the "Marajo" and "Rio Negro." At first the navigation was principally confined to the main river; and even in 1857 a modification of the government contract only obliged the company to a monthly service between Para and Manaos, with steamers of 200 tons cargo capacity, a second line to make six round voyages a year between Manaos and Tabatinga, and a third, two trips a month between Para and Cameta. The government paid the company a subvention of L. 3935 monthly. Thus the first impulse of modern progress was given to the dormant valley. The success of the venture called attention to the unoccupied field; a second company soon opened commerce on the Madeira, Purus and Negro; a third established a line between Para and Manaos; and a fourth found it profitable to navigate some of the smaller streams; while, in the interval, the Amazonas Company had largely increased its fine fleet. Meanwhile private individuals were building and running small steam craft of their own, not only upon the main river but upon many of its affluents. The government of Brazil, constantly pressed by the maritime powers and by the countries encircling the upper Amazon basin, decreed, on the 31st of July 1867, the opening of the Amazon to all flags; but limited this to certain defined points -- Tabatinga, on the Amazon; Cameta, on the Tocantins; Santarem, on the Tapajos; Borba, on the Madeira; Manaos, on the Rio Negro; the decree to take effect on the 7th of September of the same year. Para, Manaos and Iquitos are now thriving commercial centres. The first direct foreign trade with Manaos was commenced about 1874.

The local trade of the river is carried on by the English successors to the Amazonas Company -- the Amazon Steam Navigation Company. In addition to its excellent fleet there are numerous small river steamers, belonging to companies and firms engaged in the rubber trade, navigating the Negro, Madeira, Purfis and many other streams. The principal exports of the valley are india-rubber, cacao, Brazil nuts and a few other products of very minor importance. The finest quality of india-rubber comes from the Acre and Beni districts of Bolivia, especially from the valley of the Acre (or Aquiry) branch of the river Purus. Of the rubber production of the Amazon basin, the state of Para gives about 35%. The cacao tree is not cultivated, but grows wild in great abundance. There is but one railway in the whole valley; it is a short line from Para towards the coast. The cities of Para and Manaos have excellent tramways, many fine public buildings and private residences, gardens and public squares, all of which give evidence of artistic taste and great prosperity.

The number of inhabitants in the Brazilian Amazon basin (the states of Amazonas and Para) is purely a matter of rough estimate. There may be 500,000 or 600,000, or more; for the immigration during recent years from the other parts of Brazil has been large, due to the rubber excitement. The influx from the state of Ceara alone, from 1892 to 1899 inclusive, reached 98,348.

As Commander Todd, in his report to the United States government, says: "The crying need of the Amazon valley is food for the people.... At the small towns along the river it is nearly impossible to obtain beef, vegetables, or fruit of any sort, and the inhabitants depend largely upon river fish, mandioc, and canned goods for their subsistence."

Although more than four centuries have passed since the discovery of the Amazon river, there are probably not 25 sq. miles of its basin under cultivation, excluding the limited and rudely cultivated areas among the mountains at its extreme headwaters, which are inaccessible to commerce.

The extensive exports of the mighty valley are almost entirely derived from the products of the forest. (G. E. C.)

[1] Pongo is a corruption of the Quichua puncu and the Aymara ponco, meaning a door. The Pongo de Manseriche was first named Maranon, then Santiago, and later Manseric, afterwards Mansariche and Manseriche, owing to the great numbers of parakeets found on the rocks there.

[2] One of the most daring deeds of exploration ever known in South America was done by the engineer A. Wertheman. He fitted out three rafts, in August 1870, and descended this whole series of rapids and cascades from the Rio Chinchipe to Borja.

[3] Igapo is thus the name given to the recent alluvial tracts along the margins of rivers, submerged by moderate floods, whereas vargem is the term used for land between the levels of moderate and high floods, while for land above this the people use the term terra firma.

Wildlife

The Amazon River is one of the main habitats of the Boto, also known as the Amazon River Dolphin. Piranha are also notorious for dwelling in the Amazon.

External links


This page, and the pages about the tributaries derived from it originally came from the public domain 1911 encyclopedia\n