Amazon, or Amazons (Portuguese Amazonas, from an Indian word Amassona-, 'boat-destroyer'), a river of South America, and the largest stream on the face of the globe. It is known locally as Maranon, Orellana, Solimoens, Parana-tinga, and Parana-uassu. The name Maraiion (or Tungur-agua) belongs properly to the more northern of its two main head-streams, rising in Lake Lauri-cocha (Peru) about 10° 30' S. lat., 76° 10' W. long. Some writers insist that the river Apurimac, or Ucayali (the more southern of the two great head-streams), is the true Amazon. It is commonly said that the Amazon, to its remotest source, is nearly 4000 miles long; but 3000 miles is a more probable estimate. Most of the upper branches flow in deep mountain gorges of the Cordillera; east of the Cordillera the vast forest-plain is entered, which stretches from the sub-Andean foot-hills to the sea. It is a region rich in botanical treasures, having a fertile soil and a prodigiously large rainfall. Owing to this rainfall, the country is traversed by a very great number of large navigable rivers, either direct or.
indirect affluents of the Amazon. Steam navigation has been introduced on many of the larger brunches; but the natural resources of the country are very little developed.
The principal tributaries from the north are the Napo, the Putumayo, the Japura, and the Bio Negro (which connects, through the Cassi-quiare, with the Orinoco); from the south the Javary, the Jutahy, the Jurmi, the Purus, the Madeira, the Tapajos, the Xingu, and the Toc-antins. For a considerable distance the main river forms the boundary between Peru and Ecuador; but its course lies chiefly through the northern half of Brazil, its general direction being to the NNE. Its mouth is crossed by the equator. The drainage area of the river is placed at 2,500,000 sq. m., or two-thirds the area of Europe; and the main stream and its tributaries are said to afford over 25,000 miles of waterway suitable for steam navigation. The main channel, at the mouth, is 50 miles wide. The average flow of the river is placed at 2 1/4 miles per hour. The tides are noticed for about 400 miles up the river. The tidal phenomenon called the bore (here known as Pororoca) is very destructive in the main channel of the lower river, near its mouth. The name Amazon is probably derived from the female warriors (Amazons) seen by early explorers in the valley of this river; the name Maranon is derived from a voyager who visited the river in 1503; Orellana was the name of one who sailed on it in 1540.
The climate of the river-valley, though hot and very damp, is greatly mitigated by its trade-winds, which blow from the east with little interruption throughout the dry season. The river abounds in fish in very great variety of species, and turtles and alligators are plentiful, as well as porpoises and manatees. The main river is fullest from March to June inclusive, and lowest in August and September. The river is open to the commerce of all nations, but trade has been impeded by import and export duties. Para is the principal outlet by sea of the commerce of the Amazon Valley. Many useful and some highly valuable timber-trees grow on the river. One of the leading pursuits of the lower valley is the shipment to Para of india-rubber and Brazil-nuts. The western part of the basin affords quinine-yielding barks, coca, cacao, sugar, coffee, palm-wax, ipecacuanha, copaiba, sarsa-parilla, vanilla, and other valuable vegetable products, and a considerable amount of gold is procured in it.