DIVISIONS OF THE OCEAN Although the waters of the ocean form one vast con tinuous and naturally indivisible body, they are configured by the intervention of the great land masses into five more or less well-defined areas. Thus we have the Atlantic' Ocean, between the Old World on the east and the New World on the welt ; and the Pacific' Ocean, between the Old World on the east and the New World on the west. The great land masses broadening out towards the North Pole, and tapering to points towards the south, we have a vast expanse of water girdling the earth between the southern extremities of Austra lia, Africa, and America, and the Antarctic Circle, to which the name Southern Ocean has been given. The portion north of this vast area, limited by the coasts of Eastern Africa, Southern Asia, and Western Australia, forms the Indian' Ocean. The circumpolar seas, theoretically bounded by the Arctic and Antarctic circles, are also distinguished as the Arctic' and Antarctic" Oceans. The name `Southern Ocean' is given, as we have said, to the vast expanse of water in the Southern Hemisphere south of the Cape of Good Hope and Cape Horn. Geographically, however, no such division is recognised, the Atlantic, Pacific, and Indian Oceans being sup posed to extend as far south as the Antarctic Circle. But the term 'Southern Ocean' is both convenient and useful, especially in treating of oceanic circulation, and the phenomena of tides and tidal waves. Geographical writers, also, distinguish the Atlantic and Pacific north and south of the Equator, as North and South Atlantic, and North and South Pacific, Oceans, respectively.
The Atlantic Ocean extends from the Arctic Circle on the north to the Antarctic Circle on the south, having the western coasts of Europe and Africa as its eastern, and the eastern coasts of North and South America as its western, limits. Its comparatively little interruption by islands, its vast currents, and a greater length of coastline than all the other oceans together, are some of the distinguishing features of the Atlantic Ocean. Its division by the Equat'or into the North and South Atlantic also marks a change in its configuration—its northern shores being extremely irregular, the land on either side being deeply indented ; while south of the Equator its coastline is, on the whole, regular and un broken. Communication with the Arctic Ocean on the north is limited to an expanse of about fifty degrees in width between Greenland and Norway, (divided by Iceland into two unequal channels), and by Davis Strait and Baffin Bay ; while on the south it opens out broadly into the Antarctic Ocean. The principal inlets belonging to the Atlantic are ;—On its eastern side—the North Sea, (connected by the Skager Rack and Cattegat with the Baltic Sea), the English Channel, Irish Sea, St. George's Channel, Bay of Biscay, the Mediterranean, (con nected by the Dardanelles and the Sea of Marmora with the Black Sea and Sea of Azov), and the Gulf of Guinea. On its western side—Davis Strait, leading into Baffin Bay, Hudson Bay and connecting channel, Gulf of St. Lawrence, Bay of
Fundy, Gulf of Mexico, and the Caribbean Sea.
The Pacific Ocean extends from the Arctic Circle on the north to the Antarctic on the south, the western shores of America forming its eastern, and the eastern coasts of Asia and Australia its western, limits. The Pacific, though nearly twice as large as the Atlantic, is not by any means as im portant Its principal characteristic is the vast number of islands with which it is studded. The configuration of its opposite shores differ considerably—the eastern or American side being penetrated only by the Gulfs of California and Panama ; while the western side shows a number of consider able indentations forming the Sea of Kamtchatka, Gulf of Okhotsk, Sea of Japan, Yellow Sea, China Sea.
The Indian Ocean extends from the southern coasts of Asia on the north to the Antarctic Circle on the south, having Eastern Africa and a portion of the Atlantic as its western, and the Malay Archipelago and Western Australia as its eastern, boundaries. Unlike the Atlantic and Pacific Oceans, which penetrate the land mostly on their eastern and western sides, the only considerable indentations belonging to the Indian Ocean are all on its northern boundary, the principal being the Bay of Bengal, Arabian Sea, Persian Gulf, and Red Sea. With the exception of the Malay Archipelago, which forms its boundary on the east, the Indian Ocean does not contain many islands, the largest being Madagascar, off the African coast, from which it is separated by Mozambique Channel.
The Arctic Ocean is almost circumscribed by the northern coasts of America, Europe, and Asia. It encroaches on Europe in the White and Kara Seas ; on Asia in the Gulf of Obi, Anabarski Gulf; and other smaller inlets ; on America in a number of channels and bays, such as Baffin Bay, (con nected by Davis Strait with the Atlantic), Lancaster Sound, Barrow Strait, Melville Sound, Gulf of Boothia, &c., which are frozen during the greater part of the year. Navigation in the Arctic Sea is at the best difficult and dangerous, and although many expeditions have been sent out with the ex press object of reaching the north pole, all have failed; the furthest northern point being attained by Captain Markham in 1876. Our knowledge of the Arctic basin is thus imperfect, and the existence of an open sea or ice-bound land at the North Pole is not likely to be ever satisfactorily proved.
The Antarctic Ocean is the name given to the body of water comprised within the Antarctic Circle. Its boundaries are of course purely imaginary, its waters merging indefinitely into the southern expanses of the Pacific, Atlantic, and Indian Oceans. This ocean has not been explored with the same persistency as the Arctic, nor has such a high latitude ever been reached, its navigation being even more difficult and dan gerous. The portions of land already discovered in various localities bordering on and within the Antarctic Circle renders it highly probable that a vast continent surrounds the South Pole.