AMAZON, the chief river of South Amer ica and the greatest in all the world. Its source is found in the Peruvian Andes, its headwaters, the Maranon and Ucayale rivers i uniting in about long. 74° W. From long. 70 its course is wholly in Brazil, and its entire course from the source of the Ucayle to its mouth is about 3,400 miles, its width increasing from over a mile at the Peruvian frontier to 150 miles. The Amazon receives the waters of about 200 tributaries, 100 of which are navi gable, and 17 of them 1,000 to 2,300 miles in length. From the north it receives the San tiago, Morona, Pastaza, Tigre, Napo, Putn mayo, Japura, Rio Negro (a branch of which. the Cassiquiare, strangely enough connects it with the Orinoco), Uatama, Trombetas, etc; from the south the Huallaga, Ucayale, Yavari, Jutahy, Jurui, Teffe, Coary, Purus, Madeira, Tapajos, Xingu, etc. The depth varies much. From the sea to the mouth of the Rio Negro. about 750 miles in a straight line, the depth is nowhere less than 30 fathoms; higher up it varies from 10 to 12, and up to the junction of the Ucayale there is depth sufficient for large vessels. The rapidity of the stream is considerable, especially during the rainy season (January to June), when it is subject to floods. It is on the average two and t fourths miles per hour. In some places it is four, or even more, and in others as low as one mile. The river is perceptibly affected by the tides up as far as the town of Obidos, 400 miles from its mouth. The phenomenon of the bore, or as it is called on the Amazon the pororoca, occurs at the mouth of the river at spring tides on a grand scale. The waters of the ocean rush into the river in the form of huge waves 10 to 15 feet in perpendicular height, three or four of which follow each other with irresistible force. The waters of the Amazon swarm with alligators, turtles and a great variety of fish, of which Agassiz in 1866. 67 discovered 1,163 species. The country through which it flows is covered with im mense and impenetrable forests, and in regions at a distance from the larger water-courses the scarcity of mammalia bears silent testimony to the triumph of vegetation and the subordina tion of the animal kingdom. The area drained by the Amazon and its tributaries is estimated at 2,600,000 square miles. This region produces an immense variety of vegetable substances, in cluding a great many drugs, dyewoods and valuable timber trees. The products it might be made to yield by cultivation are almost in numerable, among the chief being cotton, sugar, indigo, coffee, cocoa and tobacco. The Ama zonian water system affords some 16,000 miles of river suitable for navigation. Steamers be gan to ply on the river in 1853, but years passed before its navigation was opened up to all nations. Para is the chief seat of the trade on the river, and Mangos, situated about 1,000 miles up, is also a place of commercial im portance. About 40 river, coasting, and ocean steamers now ply regularly between Path and Mangos every month, a number of them being British.
Mr. Lange (see Bibliography) describes the poror6ca, saying that in certain places "the wave travels fast,— it has traveled a measured statute mile in 90 seconds, or at the rate of about 45 miles an hour." Ex-President Roosevelt (see Bibliography), describing "the mightiest river in the world, the Amazon," says: "It runs from west to east, from the sunset to the sunrise, from the Andes to the Atlantic. The main stream flows almost along the equator. This gigantic equatorial river basin is filled with an immense forest, the largest in the world, with which no other forests can be compared save those of Western Africa and Malaysia. We were within the
southern boundary of this great equatorial forest, on a river which was not merely un known but unguessed at, no geographer hav ing ever suspected its existence. This river flowed northward toward the equator, but whither it would go, whether it would turn one way or another, the length of its course, where it would come out, the character of the stream itself, and the character of the dwellers along its banks — all these things were yet to be dis covered." Again, on pp. 333 and 334, we read: "We finally entered the wonderful Amazon itself, the mighty river which contains one tenth of all the running water of the globe. It was miles across, where we entered it; and indeed we could not tell whether the farther bank, which we saw, was that of the mainland or an island. We went up it until about mid night, then steamed up the Rio Negro for a short distance, and at one in the morning reached Mangos. Manias is a remarkable city. It is only three degrees south of the equator. Sixty years ago it was a nameless little collec tion of hovels, tenanted by a few Indians and a few of the poorest class of Brazilian peasants. Now it is a big, handsome modern city, with opera-house, tramways, good hotels, fine square and public buildings and attractive private houses. The brilliant coloring and odd archi tecture give the place a very foreign and at tractive flavor. Its rapid growth to prosperity was due to the rubber-trade. This is now far less remunerative than formerly. It will un doubtedly in some degree recover; and in any event the development of the immensely rich and fertile Amazonian Valley is sure to go on, and it will be immensely quickened when closer connections are made with the Brazilian high land country lying south of it." The mouth of the Amazon was discovered by Yafiez Pinzon in 1500, but the stream was not navigated by any European till 1540, when Francis Orellana descended it. Explorations of the river or portions of it were undertaken in later times by La Conda mine (1743-44), Humboldt (1799), Prince Ad albert of Prussia (1842), Herndon (1850), Lal lemant (1858), Bates (1861), Marcoy (1866), Agassiz (1866-67) and others; and of its tribu taries b) ilartte, Chandless, Abendroth, etc. See also in the following list of books the names of other distinguished travelers.
Bibliography.—Acufia, C. de, (A Relation of the Great River Amazons' (In
and Discoveries in South America,' London 1698) ; Bates, H. W., (The Naturalist on
River Amazons' (London 1875) ; Enoch, C. R., The Andes and the Amazon' (London 1907) ; Herndon, W. L., and Gibbon, L.,