Map of the Cassiquiare canal based on Alexander von Humboldt 1799 observations. ORiNOCO is the brand name that was used for a family of wireless networking solutions by Proxim (previously Lucent) For other uses see Rio Negro (disambiguation Rio Negro ( Portuguese: Rio Negro, Spanish: Río Negro A drainage basin is an extent of Land where Water from Rain or Snow melt drains downhill into a body of water such as a River, Venezuela (ˌvɛnəˈzweɪlə) officially the Bolivarian Republic of Venezuela (Spanish República Bolivariana de Venezuela) is a country on the (September 14 1769 &ndash May 6 1859 was a German naturalist and explorer, and the younger brother of the Prussian minister philosopher and linguist

The Casiquiare is a distributary of the upper Orinoco, which flows southward into the Rio Negro. A distributary, or a distributary channel, is a Stream that branches off and flows away from a main stream channel ORiNOCO is the brand name that was used for a family of wireless networking solutions by Proxim (previously Lucent) For other uses see Rio Negro (disambiguation Rio Negro ( Portuguese: Rio Negro, Spanish: Río Negro As such, it forms a unique natural canal between the Orinoco and Amazon river systems; it is the largest river on the planet that links two major river systems, a so-called bifurcation. The Amazon River (Rio Amazonas Río Amazonas of South America is the largest river in the world by volume with a total river flow greater than the next top ten largest rivers A distributary, or a distributary channel, is a Stream that branches off and flows away from a main stream channel

Discovery

In 1744 the Jesuit Father Roman, while ascending the Orinoco river, met some Portuguese slave-traders from the settlements on the Rio Negro. Year 1744 ( MDCCXLIV) was a Leap year starting on Wednesday (link will display the full calendar of the Gregorian calendar (or a The Society of Jesus ( Latin: Societas Iesu, SJ and SI or SJ, SI) is a Catholic religious order ORiNOCO is the brand name that was used for a family of wireless networking solutions by Proxim (previously Lucent) Portugal, officially the Portuguese Republic (República Portuguesa is a country on the Iberian Peninsula. For other uses see Rio Negro (disambiguation Rio Negro ( Portuguese: Rio Negro, Spanish: Río Negro He accompanied them on their return, by way of the Casiquiare canal, and afterwards retraced his route to the Orinoco. La Condamine, seven months later, was able to give to the Académie française an account of Father Roman's extraordinary voyage, and thus confirm the existence of this wonderful waterway first reported by Father Acuña in 1639. Charles Marie de La Condamine ( January 28, 1701 - February 4, 1774) was a French Explorer, Geographer, and L'Académie française, or the French Academy, is the pre-eminent French learned body on matters pertaining to the French language. There is an earlier Portuguese explorer Tristão da Cunha. Cristóbal Diatristán de Acuña (1597 &ndash c

But little credence was given to Father Roman's statement until it was verified, in 1756, by the Spanish Boundary-line Commission of Yturriaga and Solano. Year 1756 ( MDCCLVI) was a Leap year starting on Thursday (link will display the full calendar of the Gregorian calendar (or a Spain () or the Kingdom of Spain (Reino de España is a country located mostly in southwestern Europe on the Iberian Peninsula. In 1800 German scientist Alexander von Humboldt and French botanist Aimé Bonpland explored the river. Year -of the Julian calendar. The Gregorian calendar was 11 days ahead of the Julian calendar until Friday, but 12 days ahead since Saturday. (September 14 1769 &ndash May 6 1859 was a German naturalist and explorer, and the younger brother of the Prussian minister philosopher and linguist Aimé Jacques Alexandre Bonpland ( 22 August 1773 - 4 May 1858) was a French explorer and botanist.

Geography

The origin of Casiquiare at the River Orinoco (9 miles below the mission of Esmeralda), is about 123 meters above sea level and its mouth at the Rio Negro (affluent of the Amazon River, near the town of San Carlos is 91 meters above sea level. The Amazon River (Rio Amazonas Río Amazonas of South America is the largest river in the world by volume with a total river flow greater than the next top ten largest rivers San Carlos de Rio Negro is a town in Venezuela 's Amazonas State.

The general course is south-west, and its length, including windings, is about 200 miles. Its width, at its bifurcation with the Orinoco, is approximately 300 feet, with a current towards the Negro of three-quarters of a mile an hour; but as it gains in volume from the very numerous tributary streams, large and small, which it receives en route, its velocity increases, and in the wet season reaches 5 and even 8 miles an hour in certain stretches. A tributary is a Stream or River which flows into a mainstem (or parent river It broadens considerably as it approaches its mouth, where it is about 1750 feet in width. It will thus be seen that the volume of water it captures from the Orinoco is small in comparison to what it accumulates in its course.

In flood-time it is said to have a second connection with the Rio Negro by a branch which it throws off to the westward called the Itinivini, which leaves it at a point about 50 miles above its mouth. A flood is an overflow of an expanse of water that submerges land a deluge In the dry season it has shallows, and is obstructed by sandbanks, a few rapids and granite rocks. Its shores are densely wooded, and the 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-east. The whole line of the Casiquiare is infested with myriads of tormenting insects.

It is thus seen that this marvellous freak of nature is not, as is generally supposed, a sluggish canal on a flat tableland, but a great, rapid river which, if its upper 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 isthmus of Pimichin, which is reached by ascending the 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 craft. The isthmus is 10 miles across, with undulating ground, nowhere over 50 feet 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.

References

• This article incorporates text from the Encyclopædia Britannica Eleventh Edition, a publication now in the public domain. The Encyclopædia Britannica Eleventh Edition (1910–1911 is a 29-volume reference work that marked the beginning of the Encyclopædia Britannica The public domain is a range of abstract materials &ndash commonly referred to as Intellectual property &ndash which are not owned or controlled by anyone
• VARESCHI, Volkmar. Orinoco arriba. A través de Venezuela siguiendo a Humboldt. Caracas: Ediciones Lectura, 1959

External links

• Alexander von Humboldt and the Casiquiare River
• The point where the Casiquiare bifurcates from the Orinoco, on Google Maps
• Wikimapia satellite image displaying locations of both the beginning (principio) and the end (desague) of the Casiquiare Canal.