AMAZON, MARANON, ORELLANA, or SOLIMOENS, a river of South America, the largest in the world. Its head stream in either the Ucayale or Apurimac, which raises in Peru about 16°S. lat., and 72° W. long; or the more northerly Marañon, also called Tunguragua, which flows from Lake Lauricocha, 10° 30' S. Lat., and 76° 10' W. long. The former is the longer river, but the latter has perhaps the weight of authority in its favour. The Marañon flows in a north-westerly direction, parallel to the Ucayale, as far as 6° S. Lat., when it bends to the north-east, and, on reaching the frontiers of Equador, turns almost due east. It thence forms the boundary between Equador and Peru, with and easterly direction. Until it joins the Ucayale. The united river continues to separate Equador and Peru as long as these countries are conterminous, and thereafter strikes through, Brazil, the general direction being north-north-east. It finally discharges itself into the Atlantic under the equator.
From the source of the Apurimac to the ocean this mighty river has a length including windings, of nearly 4000 miles. It receives enormous tributaries --- from the north, the Napo and the Putumayo, each about 700 miles long; the Yapura, 1000 miles; the Negro, 1400; as well as others of less importance: from the south, besides the Yavari, the Yutai, the Yurua, Tefe, the Puro, and others, there are the Madeira, of nearly 2000 miles; the Topayos, of 1200; the Xingu, of 1300; and the Tocantins, of 1200. In addition to these, the Huallaga, of 500 miles, joins the Marañon, from the south, above its union with the Ucayale. The area drained by the Amazon and its tributaries is probably not less than 2,500,000 square miles, or more than a third part of South America.
The breadth of the river, of course, varies at different points. At some distance below Jean, on the Maranon, it was found to be 860 feet wide; at a pass called the Pongo de Manseriche its bed is suddenly contracted from 250 to 25 fathoms, being enclosed on either side by rocks, which rise like perpendicular walls to a great height; at the junction with the Napo its breadth has increased to 900 fathoms. Between the Negro and the Madeira it has the breadth of a league which extends to two leagues at those parts where islands abound; but during the annual rise of the water it covers a great part of the adjacent country, and has then no determinate limits. The main mouth is about 50 miles wide above the island of Caviana, but the whole delta, including the Para mount and the island of Joannes is nearly 200 miles from shore to shore.
The depth of the Amazon in some parts exceeds 50 fathoms, and the river is navigable for vessels of the largest size up to the confluence of the Maranon and the Ucayale. Beyond this point vessels of a smaller size can proceed as far as San Borja, on the Maranon, and a considerable distance up the Ucayale and the Huallaga.
The velocity of the water above San Borja so greatly exceeds the average (which is about 2 1/4 miles an hour), that navigation become difficult, and among the rapids is impossible, even to canoes.
Nearly all the branches of the Amazon are navigable to a great distance from their junction with the main stream; and collectively the whole presents an extent of water communication unparalleled in any other part of the globe. It may be mentioned too, that as the wind and current are usually, at least from July to December, opposed to each other, a vessel can make her way either up or down with great facility by availing herself of her sails in the one case, and committing herself to the force of the current in the other. Since the introduction of steamers, however, this circumstance is of less importance.
The influence of the tides is felt 400 miles above the mouth of the Amazon, while on the other hand the river current is distinctly perceptible in the ocean for more than 200 miles from the shore. The curious tidal phenomenon called the bore, or proroca, is thus described by La Condamine: ---
"During three days before the new and full moons, the period of the highest tides, the sea, instead of occupying six hours to reach, its flood, swells to its highest limit in one or two minutes. The noise of this terrible flood is heard five or six miles off, and increased as it approaches. Presently you see a liquid promontory 12 or 15 feet high, followed by another, and another, and sometimes by a fourth. These watery mountains spread across the whole channel, and advance with a prodigious rapidity, rending and crushing everything in their way. Immense trees are sometimes uprooted by it, and sometimes whole tracts of land are swept away."
The Amazon traverses a region thickly covered with lofty forests, which are the haunts of the jaguar, bear, panther and other wild animals, and are inhabited by numerous small tribes of savages, among whom the Spaniards and Portuguese have established missionaries. The river abounds with fish, many of which are delicious eating; and turtles of an excellent quality are numerous. Large alligators may be frequently seem stretched motionless in the mud like trunk of trees. The name Amazon (which is also written Amazons and Amazonas) is derived from the Indian word Amassona, or "boat-destroyer.", the reference being to the destructive proroca. According to native usage, the name Amazon ought to be restricted to the lower part of the river, below the mouth of the junction of the Marañon and the Ucayale, being termed by the natives Solimoens. The other two designations by which the river is sometimes known owe their origin respectively to Francis Orellana, who in 1540 sailed from the mouth of the Rio Napo to the ocean, and Marañon, who visited the upper waters in 1513. Yañez Pinzon, however, visited the river before either, having discovered the mouth in 1500. (See the works of Bates, Wallace, and W. H. Edwards, and the article BRAZIL.) (--)