THE ATLANTIC OCEAN ITS BOUNDARIES AND EXTENT The Atlantic Ocean, though considerably smaller than the Pacific, is by far the more important, and, having been for centuries the great highway of commerce between the more civilized nations of the earth, it is also much better known. Bounded on the east by the Old World, and on the west by the New World, its huge, trough-like basin extends from the Arctic Circle on the north to the Antarctic Circle on the south, somewhat in the shape of the letter S ; and as the projections on the one side correspond generally to the inden tations on the other side, the opposite shores of the Atlantic preserve a remarkable parallelism, not inaptly shown by the name occasionally given to it—namely, the " Atlantic CanaL" The coast-line of this ocean is rendered so irregular by the numerous seas, bays, gulfs, and other inlets, that the student will obtain a better idea of its configuration by a careful examination of the accompanying map, than by any merely verbal description, however full and accurate. Besides its comparative narrowness and irregularity of outline, and con sequent enormous extent of coastline—greater, indeed, than that of all the other oceans taken together—the distinguish ing features of the Atlantic Ocean are its comparatively few islands ; the greater irregularity of coastline and number of islands in its northern than in its southern division ; the magnitude, regularity, and velocity of its currents ; its Sar gasso Sea, round which, in an endless cycle, the great Equa torial current, the Gulf Stream, and African current flow ; the frequency and violence of the gales which sweep over it, rendering it the stormiest and most dangerous to navigation of all the great oceans ; its great variety of temperature, ex tending from the frozen basin of the Arctic, through the tropics, to the ice-bound Antarctic Ocean ; its enormous cli matical influence, directly affecting a drainage area of nearly 20,000,000 square miles ; its position as the great commercial highway of the more civilized nations of the world, and, con sequently, its intimate connection with the promotion and diffusion of an advanced civilization.
As a glance at the map will show, both sides of the " Atlantic Canal " preserve a generally north-east to south west direction from the Arctic Circle to the Tropic of Cancer; thence to Cape St. Roque on the American, and the mouth of the Congo, or Livingstone River, on the African, coast, the general trend of both sides is in an exactly opposite direction —namely, from north-west to south-east. Thus far the general parallelism of the opposite shores is remarkably maintained ; but farther south the African coast trends nearly due south, while the South American coast diverges to the south-west. But while the former terminates in Cape Agulhas (34° 49' S. lat.), the latter extends 20° further south to Cape Horn. Theoretically, the waters of the Atlantic south of Cape Agul has are divided from those of the contiguous Indian Ocean by an imaginary line drawn along the 20th meridian from that cape to the Antarctic Circle ; on the west, the limiting line between the Atlantic and Pacific Oceans south of Cape Horn extends meridionally from that cape to Graham Land. The following table, showing the countries of the same latitude on the opposite sides of the Atlantic, may be of service to the student, if carefully read over and compared with the map :— 161. The area of the Atlantic has been variously estimated at from 25 to 35 millions of square miles. One high autho rity I gives 35,160,000 square miles as the superficial extent of this ocean, which thus occupies nearly a fifth part of the entire surface of the earth. While its length is upwards of 9,000 miles, its breadth varies from 900 miles between Nor way and Greenland, to upwards of 5,000 miles between Cape Blanco and Mexico. Between Portugal and the United States the distance is scarcely 3,400 miles, further diminished be tween Ireland and Labrador to 2,000 miles. Under the equa tor the width is not less than 4,200 miles, but between Sierra Leone and Brazil it is only 1,700 miles.. Southward it gradu ally widens, until the Cape of Good Hope and the opposite coasts of La Plata are over 4,000 miles, apart.