Page:1902 Encyclopædia Britannica - Volume 25 - A-AUS.pdf/824

 768

ATLANTIC — AT LANTIC

$9,500,000 of capital, and 8684 persons. Chief among these were cotton manufactories, in which $1,900,000 were invested, and foundries and machine shops, with nearly $1,000,000. Lumber and furniture factories are also of great importance. The assessed valuation of property, real and personal, was, in 1899, $52,240,058, the tax rate $21.60 per $1000, and the indebtedness of the municipality $2,808,910. The death-rate, 23-01 per 1000, is enhanced by the large proportion of negroes among the population. Since the Civil War, which practically destroyed it, the city has grown with great rapidity. Population (1880), 37,409; (1890), 65,533; (1900), 89,872, of whom 2531 were foreign-born and 35,912 were negroes. Atlantic, capital of Cass county, Iowa, U.S.A., situated on the East Nishnabotna river, at the intersection of the Chicago, Rock Island, and Pacific railway with a branch of the Chicago, Burlington, and Quincy railway. Population (1890), 4351 ; (1900), 5046. Atlantic City, a city of Atlantic county, New Jersey, U.S.A., situated in 39° 22' N. lat. and 74° 26' W. long., on a sand-bar running parallel with the coast, and separated from the mainland by a strip of marsh about five miles in breadth. The city is but slightly elevated above tide-level, is regularly laid, and is divided into four wards. Water is supplied by pumping, the water-works being privately owned. It is a popular seaside resort both in summer and winter, especially with dwellers in Philadelphia, with which city it is connected by two railways, the Atlantic City (Philadelphia and Reading system) and the West Jersey and Seashore (Pennsylvania system). It is a city of hotels and boarding - houses, and in the summer season has a large floating population, estimated at 100,000. The first settlement was made about 1783, and the place received a city charter in 1852. Population (1880), 5477; (1890), 13,055; (1900), 27,838. Atlantic Ocean.—The Atlantic Ocean forms a belt of water, roughly of an S-shape, between the western coasts of Europe and Africa and the eastern coasts of North and South America. It extends northwards to the Arctic Basin and southwards to the Great Southern Ocean. For purposes of measurement the polar boundaries are taken to be the Arctic and Antarctic circles, although in discussing the configuration and circulation it is impossible to adhere strictly to these limits. The Atlantic Ocean consists of two characteristic divisions, the geographical equator forming a fairly satisfactory line of division into North and South Atlantic. The North Atlantic, by far the best known of the main divisions of the hydrosphere, is remarkable for the immense length of its coast-line and for the large number of enclosed seas connected with it, including on the western side the Caribbean Sea and Gulf of Mexico, the Gulf of St Lawrence, and Hudson Bay, and on the eastern side the Mediterranean and Black Sea, the North Sea, and the Baltic. The North Atlantic is connected with the Arctic Basin by four main channels: (1) Hudson Strait, about 60 miles wide, communicating with the gulfs and straits of the North American Arctic archipelago; (2) Davis Strait, about 200 miles wide, leading to Baffin Bay; (3) Denmark Strait, between Greenland and Iceland, 130 miles wide; and (4) the “Norwegian Sea,” about 400 miles wide, extending from Iceland to the Faroe Islands, the Shetland Islands, and the coast of Norway. The width of the North Atlantic in lat. 60°, approximately where it breaks up into the branches just named, is nearly 2000 miles; in about lat. 50° N., the coasts of Ireland and Newfoundland approach to 1750 miles; the breadth

OCEAN

then increases rapidly to lat. 40° N., and attains its maximum of 4500 miles in lat. 25° N.; farther south the minimum breadth is reached between Africa and South America, Cape Palmas being only 1600 miles distant from Cape St Roque. In marked contrast to this, the South Atlantic is distinguished by great simplicity of coast-line; inland seas there are none, and it attains its greatest breadth as it merges with the Southern Ocean; in lat. 35° S. the width is 3700 miles. The total area of the North Atlantic, not counting inland seas connected with it, is, according to Karstens, 36,438,000 square kilometres, or 10,588,000 square miles; including the inland seas the area is 45,641,000 square kilometres, or 13,262,000 square miles. The area of the South Atlantic is 43,455,000 square kilometres, or 12,627,000 square miles. Although not the most extensive of the great oceans, the Atlantic has by far the largest drainage area. The “long slopes” of the continents on both sides are directed towards the Atlantic, which accordingly receives the waters of a large proportion of the great rivers of the world, including the St Lawrence, the Mississippi, the Orinoco, the Amazon, the rivers of the La Plata, the Congo, the Niger, the Loire, the Rhine, the Elbe, and the great rivers of the Mediterranean and the Baltic. Murray estimates the total area of land draining to the Atlantic to be 13,432,000 square miles, or with the Arctic area nearly 20,000,000 square miles, nearly four times the area draining to the Pacific Ocean, and almost precisely four times the area draining to the Indian Ocean. Murray’s calculations give the amount of precipitation received on this area at 15,800 cubic miles annually, and the river discharge from it at 3900 cubic miles. The dominant feature of the relief of the Atlantic basin is a submarine ridge running from north to south from about lat. 50° N. to lat. 40° S., almost exactly in the central line, and following the S-shape of the coasts. Over this ridge the average depth is about 1700 fathoms. Towards its northern end the ridge widens and rises to the plateau of the Azores, and in about 50° N. lat. it merges with the “ Telegraph Plateau,” which extends across nearly the whole ocean from Ireland to Newfoundland. North of the fiftieth parallel the depthsdiminish towards the north-east, two long submarine ridges of volcanic origin extend north-eastwards to the south-west of Iceland and to the Faroe Islands, and these, with their intervening valleys, end in a transverse ridge connecting Greenland, through Iceland and the Faroe Islands, with North-western Scotland and the continental mass of Europe. The mean depth over this ridge is about 250 fathoms, and the maximum depth nowhere reaches 500 fathoms. The main basin of the Atlantic is thus cut off from the Arctic basin, with which the area north of the ridge has complete deep-water communication. This intermediate region, which has Atlantic characteristics down to 300 fathoms, and at greater depths belongs more properly to the Arctic Sea, commonly receives the name of Norwegian Sea. On both sides of the central ridge deep troughs extend southwards, from the Telegraph plateau to the Southern Ocean, the deep water coming close to the land all the way down on both sides. In these troughs the depth is seldom much less than 3000 fathoms, and this is exceeded in a series of patches to which Murray has given the name of “ Deeps.” In the eastern trough the Peake deep lies off the Bay of Biscay in 20° W. long., Monaco deep and Chun deep off the north-west of Africa, Moseley deep off the Cape Yerde Islands, Krech deep off the Liberian coast, and Buchanan deep off the mouth of the Congo. The western trough extends northwards into Davis Strait, forming a depression in the Telegraph plateau; to the south of Newfoundland