Atlantic Ocean, The, so named from Mt. Atlas, the vast body of water situated between the continent of America on the west and Africa and Europe on the east. Geographers usually consider the Arctic and Antarctic circles as its polar boundaries. The area is about 25,000,000 square miles. Its breadth in a direct east and west line varies. The distance from the most easterly point of Brazil to the African coast is 1,730 miles; from Florida to the African coast 4.150; and from Greenland to Norway 930. The eastern coast line is over 30,000 miles in length, the windings of the Mediterranean included; the western coast is over 55,000 miles in length if carried into all the gulfs and bays. The entire coast line of the Atlantic equals that of the Pacific and the Indian Oceans combined. The greatest depth thus far found, 27,366 feet, is not far to the north of Porto Rico. This depression is exceeded only by the altitude of Mt. Everest and two of its neighbors in Central Asia. The South Atlantic appears from soundings to be separated from the North Atlantic by a ridge running from Ascension Island to St. Paul. Soundings connected with the laying of cables have determined the fact that the North Atlantic is divided into two broad north and south valleys, each 500 miles wide, by an intervening ridge or plateau 400 miles wide, the ends of which appear to rest at Iceland and the Azores. The waters of the tropics are denser and contain more salt than is found to be the case nearer the equator or toward either pole. The salt of the ocean is said to be somewhat more than one-fortieth of its entire weight. Deep sea dredgings reveal the fact that the bottom is covered with a soft ooze, the product of minute shells, the covering of microscopic animals. The currents of the Atlantic may be dismissed as too complex for description within the limits of this article. In the simplest words, a powerful equatorial current following the equator westward splits on the eastern shoulder of South America. The southeastern branch runs southward along the coast of Brazil and forms an eddy or circuit in the South Atlantic, rejoining the equatorial current again off the coast of Africa. The northern branch coasts along the northern shore of South America, enters the Caribbean, and emerges from the great bay as the Gulf Stream. In its northeasterly course this stream branches and sends a current along the western coast of Greenland; another follows the western coast of the British Isles and Norway; and the third, reinforced by an undertow of Arctic waters, sweeps southward east of the Azores and past the coast of Guinea to complete the northern eddy and join the equatorial current. The Atlantic is a stormy sea. Its waters are full of life. Whales, porpoises, sharks, vast shoals of herring, mackerel, and cod are found in its shallows, and its shores are thronged with gulls, cormorants, and all sorts of sea birds. Though not the largest or the deepest ocean, the Atlantic receives eighteen out of thirty-three, or over half of the world's great rivers. See PACIFIC; ANTARCTIC; ARCTIC.