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CASIQUTARE CANAL

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Originally appearing in Volume V01, Page 790 of the 1911 Encyclopedia Britannica.
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CASIQUTARE See also:

CANAL . In 1744 the Jesuit See also:Father See also:Roman, while ascending the See also:Orinoco See also:river, met some Portuguese slave-traders from the settlements on the Rio See also:Negro. He accompanied them on their return, by way of the Casiquiare canal, and after-wards retraced his route to the Orinoco. La Condamine, seven months later, was able to give to the See also:French See also:Academy an See also:account of Father Roman's extraordinary voyage, and thus confirm the existence of this wonderful waterway first reported by Father Acura in 1639. But little See also:credence was given to Father Roman's statement until it was verified, in 1956, by the See also:Spanish Boundary-See also:line See also:Commission of Yturriaga y Solano. The actual See also:elevation of the canal above See also:sea-level is not known, but is of See also:primary importance to the study of the See also:hydrography of See also:South See also:America. Travellers in See also:general give it at from 400 to goo ft., but, after much study of the question of altitudes throughout South America, the writer believes that it does not exceed 300 ft. The canal connects the upper Orinoco, 9 M. below the See also:mission of Esmeraldas, with the Rio Negro affluent of the See also:Amazon near the See also:town of See also:San See also:Carlos. The general course is south-See also:west, and its length, including windings, is about 200 M. Its width, at its bifurcation with the Orinoco, is approximately 300 ft., with a cur-See also:rent towards the Negro of three-quarters of a mile an See also:hour; but as it gains in See also:volume from the very numerous tributary streams, large and small, which .it receives en route, its velocity increases, and in the wet See also:season reaches 5 and even 8 m. an hour in certain stretches. It broadens considerably as it approaches its mouth, where it is about 1750 ft. in width. It will thus be seen that the volume of See also:water it captures from the Orinoco is small in comparison to what it accumulates in its course.

In See also:

flood-See also:time it is said to have a second connexion with the Rio Negro by a See also:branch which it throws off to the westward called the Itinivini, which leaves it at a point about 50 M. above its mouth. In the dry season it has shallows, and is obstructed by sandbanks, a few rapids and See also:granite rocks. Its shores are densely wooded, and the See also:soil more fertile than that along the Rio Negro. The general slope of the plains through which the canal runs is south-west, but those of the Rio Negro slope south-See also:east. The whole line of the Casiquiare is infested with myriads of tormenting See also:insects. A few miserable See also:groups of See also:Indians and See also:half-breeds have their small villages along its See also:southern portion. It is thus seen that this marvellous freak of nature is not, as is generally supposed, a sluggish canal on a See also:flat tableland, but a See also:great, rapid river which, if its upper See also:waters had not found contact with the Orinoco, perhaps by cutting back, would belong entirely to the Negro branch of the Amazon. To the west of the Casiquiare there is a much shorter and more facile connexion between the Orinoco and Amazon basins, called the See also:isthmus of Pimichin, which is reached by ascending the See also:Terni branch of the Atabapo affluent of the Orinoco. Although the Terni is somewhat obstructed, it is believed that it could easily be made navigable for small See also:craft. The isthmus is ro m. across, with undulating ground, nowhere over 50 f t. high, with swamps and marshes. It is much used for the transit of large canoes, which are hauled across it from the Terni river, and which reach the Negro by the little stream called the Pimichin. The YAPURA.

West of the Negro the Amazon receives three more imposing streams from the See also:

north-west—the Yapura, the See also:Ica or Putumayo, and the Napo. The first was formerly known as the Hyapora, but its Brazilian See also:part is now called the Yapura, and its Colombian portion the Caqueta. Banao de Marajo gives it 60o m. of navigable. stretches. Jules Crevaux, who descended it, describes it as full of obstacles to. See also:navigation, the current very strong and the stream frequently interrupted by rapids and cataracts. It rises in the Colombian See also:Andes, nearly in See also:touch with the See also:sources of the Magdalena, and augments its volume from many branches as it courses through See also:Colombia. It was See also:long supposed to have eight mouths; but See also:Ribeiro de Sampaio, in his voyage of 1774, determined that there was but one real mouth, and that the supposed others are all furos or canos.' In 1864-1868 the Brazilian See also:government made a somewhat careful examination of the Brazilian part of the river, as far up as the rapid of Cupaty. Several very easy and almost See also:complete water-routes exist between the Yapura and Negro across the See also:low, flat intervening See also:country. Baran de Marajo says there .are six of them, and one which connects the upper Yapura with the Uaupes branch of the Negro; thus the See also:Indian tribes of the respective valleys have facile contact with each other. The ICA or PUTUMAYO, west of and parallel to the Yapura, was found more agreeable to navigate by Crevaux. He ascended it in a steamer See also:drawing 6 ft. of water, and See also:running See also:day and See also:night. He reached Cuemby, 800 m. above its mouth, without finding a single rapid.- Cuemby is only 200 m. from the Pacific Ocean, in a straight line, passing through the town of See also:Pasto in southern Colombia. There was not a See also:stone to be seen up to the See also:base of the Andes; the river See also:banks were of argillaceous See also:earth and the bottom of See also:fine See also:sand.

. The NAFO rises on the flanks of the volcanoes of Antisana, Sincholagua and See also:

Cotopaxi. Before it reaches the plains it receives a great number of small streams from impenetrable, saturated and much broken mountainous districts, where the dense and varied vegetation seems to fight for every square See also:foot of ground. From the north it is joined by the river See also:Coca, having its sources in the See also:gorges of Cayambe on the See also:equator, and also a powerful river, the Aguarico, having its headwaters between Cayambe and the Colombian frontier. From the west it receives a secondary tributary, the Curaray, from the Andean slopes, between Cotopaxi and the See also:volcano of Tunguy.gua. From its Coca branch to the mouth of the Curaray the Napo is full of snags and shelving sandbanks, and throws out numerous calms among See also:jungle-tangled islands, which in the wet season are flooded, giving the river an immense width. From the Coca to the Amazon it runs through a forested See also:plain where not a See also:hill is visible from the river—its uniformly level banks being only interrupted by swamps and lagoons. From the Amazon the Napo is navigable for river craft up to its Curaray branch, a distance of about 216 m., and perhaps a few See also:miles farther; thence, by painful See also:canoe navigation, its upper waters may be ascended as far as See also:Santa See also:Rosa, the usual point of embarkation for any venturesome traveller who descends from the See also:Quito tableland. The Coca river may be penetrated as far up as its See also:middle course, where it is jammed between two See also:mountain walls, in a deep See also:canyon, along which it dashes over high falls and numerous reefs. This is the stream made famous by the expedition of Gonzalo See also:Pizarro. The NANAY is the next Amazon tributary of importance west of the Napo. It belongs entirely to the lowlands, and is very crooked, has a slow current and divides much into canos and strings of lagoons which flood the flat, low areas of country on either See also:side. It is simply the drainage ditch of districts which are extensively overflowed in the See also:rainy season.

See also:

Captain See also:Butt ascended it 195 m., to near its source. The See also:TIGRE is the next west of the Nanay, and is navigable for 125 M. from its confluence with the Amazon. Like the Nanay, it belongs wholly to the plains. Its mouth is 42 M. west of the junction of the Ucayali with the Amazon. Continuing west from the Tigre we have the Parinari, Chambira, and Nucuray, all See also:short See also:lowland streams, resembling the Nanay in See also:character. The PASTAZA (the See also:ancient river Sumatara) is the next large river we meet. It rises on the Ecuadorian-tableland, where a branch from the valley of See also:Riobamba unites with one from the See also:Latacunga See also:basin and breaks through the inland range of the Andes; and joined, afterwards, by several important tributaries, finds its way south-east among the gorges; thence it turns southward into the plains, and enters the Amazon at a point about 6o m. west of the mouth of the Huallaga. So far as ' A caffo, like furo,is a See also:kind of natural canal; it forms a lateral See also:discharge for surplus water from a river.known, it is a stream of no value except for canoe navigation. Its rise and fall are rapid. and uncertain, and it is shallow and full of sandbanks and snags. It is a terrible river when in flood. The MORONA flows parallel to the Pastaza and immediately to the west of it, and is the last stream of any importance on the See also:northern side of the Amazon before reaching the Pongo de Manseriche. It is formed from a multitude of water-courses which descend the slopes of the Ecuadorian Andes south of the gigantic volcano of Sangay; but it soon reaches the plain, which commences where it receives its Cusulima branch.

The MORONA is navigable for small craft for about 300 M. above its mouth, but it is extremely-tortuous. Canoes may ascend many of its branches, especially the Cusulima and the Miazal, the latter almost to the base of Sangay. The Morona has been the See also:

scene of many See also:rude explorations, with the See also:hope of finding it serviceable as a commercial route between the inter-Andean tableland of See also:Ecuador and the Amazon river. A river called the Paute dashes through the eastern Andes from the valley of See also:Cuenca;' and a second, the See also:Zamora, has broken through the same range from the basin of See also:Loja. Swollen by their many affluents, they reach the lowlands and unite their waters to See also:form the See also:Santiago, which flows into the Maranon at the See also:head of the Pongo de Manseriche. There is but little known of a trustworthy character regarding this river, but See also:Wolf says that it is probably navigable up to the junction of the Paute with the Zamora. The See also:Main River. The A; zoN MAIN RsvER is navigable for ocean steamers as far as See also:Iquitos, 2300 M. from the sea, and 486 m. higher up for vessels drawing 14 ft. of water, as far as Achual Point. See also:Physical Beyond that, according to See also:Tucker, confirmed by charactei-Wertheman, it is unsafe; but small steamers frequently "tics. ascend to the Pongo de Manseriche, just above Achual Point The See also:average current of the Amazon is about 3 M. an hour; but, especially in flood, it dashes through some of its contracted channels at the See also:rate of 5 M. The U.S. steamer "See also:Wilmington" ascended it to Iquitos in 1899. See also:Commander Todd reports that the average See also:depth of the river in the height of the rainy season is 120 ft. It commences to rise in See also:November, and increases in volume until See also:June, and then falls until the end of See also:October.

The rise of the Negro branch is not synchronous ; for the steady rains do not commence in its valley until See also:

February or See also:March. By June it is full, and then it begins to fall with the Amazon. According to See also:Bates, the See also:Madeira " rises and sinks " two months earlier than the Amazon. The Amazon at times broadens to 4 and 6 m. Occasionally, for long distances, it divides into two main streams with inland, lateral channels, all connected by a complicated See also:system of natural canals, cutting the low, flat igapo lands, which are never more than 15 ft. above low river, into almost numberless islands? At the narrows of Obidos, 400 M. from the sea, it is compressed into a single See also:bed a mile wide and over 200 ft. deep, through which the water rushes at the rate of 4 to 5 M. an hour. In the rainy season it inundates the country throughout its course to the extent of several See also: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 See also:Para 12 ft. The first high See also:land met in ascending the river is on the north See also:bank, opposite the mouth of the Xingu, and extends for about 150 M. Up, as far as See also:Monte Alegre. It is a See also:series of steep, table-topped hills, cut down to a kind of See also:terrace which lies between them and the river.

Monte Alegre reaches an See also:

altitude of several hundred feet. On the south side, above the Xingu, a line of low bluffs extends, in a series of See also:gentle curves with hardly any breaks nearly to See also:Santarem, but a considerable distance inland, bordering the flood-plain, which is many miles wide. Then they See also:bend to the south-west, and, abutting upon the See also:lower Tapajos, See also:merge 1 Igapo is thus the name given to the See also:recent alluvial tracts along the margins of See also:rivers, submerged by moderate floods, whereas vargem is the, See also:term used for land between the levels of moderate and high floods, while for land above this the See also:people use the term terra firma. into the bluffs which form the terrace margin of that river valley. The next high land on the north side is Obidos, a See also: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 See also:Manaos, they are See also:rolling hills; but from the Negro, for 600 m., as far up as the See also: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 15oo m., 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 See also:

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 See also:area of the Amazon basin above Obidos is about 1,945,000 sq. m., and, below, only about 423,000 sq. m., or say 20 %, exclusive of the 354,000 sq. m. 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 See also:statute m.; but this includes the ocean outlet, 40 M. 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 See also:island about the See also:size of the See also:kingdom of See also:Denmark lying in the mouth of the Amazon. Following the See also:coast, a little to the north of Cabo do Norte, and for too m. along its See also:Guiana margin up the Amazon, is a See also:belt of half-submerged islands and shallow sandbanks. Here the tidal phenomenon called the See also: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 ro to 15 M. an hour, with a breaking See also: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 See also:delta. The Amazon is not so much a river as it is a gigantic See also:reservoir, extending from the sea to the base of the Andes, and, in the wet season, varying in width from 5 to 400 M. See also:Special See also: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 See also:world would also be termed great. For 350 years after the See also:discovery of the Amazon, by See also:Pinzon, the Portuguese portion of its basin remained almost an undis- turbed See also:wilderness, occupied by Indian tribes whom the POP1+/a" See also:food quest had split into countless fragments.

It is tcn, See also:

trade, doubtful if its indigenous inhabitants ever exceeded one to every 5 sq. m. of territory, this being the maxi-mum it could support under the existing conditions of the See also:period in question, and taking into account Indian methods of See also: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 See also:European See also:civilization. The See also:total See also:population of the Brazilian portion of the Amazon basin in 1850 was perhaps 300,000, ofwhom about two-thirds were See also:white and slaves, the latter numbering about 25,000. The See also:principal commercial See also: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 moo to 15oo population; but all the remaining villages, as far up as Tabatinga, on the Brazilian frontier of See also:Peru, were wretched little groups of houses which appeared to have timidly effected a lodgment on the river bank, as if they feared to See also: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 500,000. On the 6th of See also:September 1850 the See also:emperor, Dom Pedro II., sanctioned a See also:law authorizing See also:steam navigation on the Amazon, and confided to an illustrious Brazilian, Barao Mau& (Irineu Evangilista de See also:Sousa), the task of carrying it into effect. He organized the " Compania de Navigacao e Commercio do See also:Amazonas" at Rio de Janeiro in 1852; and in the following See also: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 See also:contract only obliged the See also:company to a monthly service between Para and Manaos, with steamers of 200 tons See also:cargo capacity, a second line to make six See also:round voyages. a year. between Manaos and Tabatinga, and a third, two trips a See also:month between Para and Cameta. The government paid the company a subvention of 3935 monthly. Thus the first impulse of See also:modern progress was given to the dormant valley. The success of the venture called attention to the unoccupied See also:field; a second company soon opened See also:commerce on the Madeira, Pm-6s and Negro; a third established a line between Path and Manaos; and a See also:fourth found it profitable to navigate some of the smaller streams; while, in the See also:interval, the Amazonas Company had largely increased its fine See also:fleet. Meanwhile private individuals were See also:building and running small steam craft of their own, not only upon the main river but upon many of its affluents.

The government of See also:

Brazil, constantly pressed by the maritime See also:powers and by the countries encircling the upper Amazon basin, decreed, on the 31st of See also: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 See also:decree to take effect on the 7th of September of the same year. Para, Manaos and Iquitos are now thriving commercial centres. The first See also:direct See also:foreign trade with Manaos was commenced about 1874. The See also:local trade of the river is carried on by the See also: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 See also:rubber trade, navigating the Negro, Madeira, Pur6s and many other streams. The principal exports of the valley are See also:india-rubber, cacao, Brazil nuts and a few other products of very See also:minor importance. The finest quality of indiarubber comes from the See also:Acre and Beni districts of See also:Bolivia, especially from the valley of the Acre (or Aquiry) branch of the river See also:Purim. Of the rubber See also:production of the Amazon basin, the See also:state of Path gives about 35 %. The cacao See also:tree is not cultivated, but grows See also: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 tram-ways, many fine public buildings and private residences, gardens and public squares, all of which give evidence of See also:artistic See also:taste and great prosperity. The number of inhabitants in the Brazilian Amazon basin (the states of Amazonas and Path) is purely a See also:matter of rough estimate.

There may be Soo,000 or 600,00o; or more; for the See also:

immigration during recent years from the other parts of Brazil has been large, due to the rubber excitement. The influx from the state of See also:Ceara alone, from 1892 to 1899 inclusive, reached 98,348. As Commander Todd, in his See also:report to the See also: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 See also:beef, vegetables, or See also:fruit of any sort, and the inhabitants depend largely upon river See also: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. m. 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 See also:forest. (G. E.

End of Article: CASIQUTARE CANAL

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