AUSTRALIA (older name, New Hol land), the largest island in the world, a sea-girt continent, lying between the In dian and Pacific Oceans, S. E. of Asia. It is separated from New Guinea on the N. by Torres Strait, from Tasmania on the S. by Bass Strait. It is divided into two unequal parts by the Tropic of Cap ricorn, and consequently belongs partly to the South Temperate, partly to the Torrid Zone. The Commonwealth con sists of six colonies called the Original States of New South Wales, Victoria, Queensland, South Australia, Western Australia, and Tasmania. The act pro viding for a Federal Union constituting the Commonwealth was passed by the British Parliament in 1900. On Jan. 1, 1911, the north territory was transferred by South Australia to the Common wealth, and on the same date a portion of New South Wales, consisting of 912 square miles, was vested in the Common wealth for the purpose of forming the Federal Territory containing the seat of the Commonwealth Government. This area was increased in 1917 to 940 square miles.
Area and Population.—Their area and population in 1918 are given as follows: The population of the smaller divisions is as follows: Tasmania, 202,842; Northern Terri tory, 3,269; Federal Territory, 2,404.
The estimated total population in 1919 was 5,140,543.
Sydney, the capital of New South Wales, Melbourne, the capital of Victoria, Adelaide, the capital of South Australia, and Brisbane, the capital of Queensland, are the chief towns.
Topography.—Although there are nu merous spacious harbors on the coasts, there are few remarkable indentations; the principal being the Gulf of Carnen taria, on the N., the Great Australian Bight, and Spencer Gulf, on the S. The chief projections are Cape York Penin sula and Arnhem Land in the N. Par allel to the N. E. coast runs the Great Barrier Reef for 1,000 miles.
Geology.—The interior, so far as ex plored, is largely composed of rocky tracts and barren plains with little or no water. The whole continent forms an immense plateau, highest in the E., low in the center, and with a narrow tract of land usually intervening between the elevated area and the sea. The base of
the table-land is granite, which forms the surface rock in a great part of the S. W., and is common in the higher grounds along the E. side. Secondary (cretaceous) and tertiary rocks are largely developed in the interior. Silu rian rocks occupy a large area in South Australia, on both sides of Spencer Gulf. The mountainous region in the S. E. and E. is mainly composed of volcanic, silu rian, carbonaceus, and carboniferous rocks yielding good coal. The highest and most extensive mountain system is a belt about 150 miles wide, skirting the whole eastern and southeastern border of the continent, and often called, in whole, or in part, the Great Dividing Range, from forming the great water shed of Australia. A part of it, called the Australian Alps, in the S. E. contains the highest summits in Australia, Mt. Kosciusko (7,175 feet), Mt. Clark (7,256), and Mt. Townshend (7,353). West of the Dividing Range are ex tensive plains or downs admirably adapted for pastoral purposes. The deserts and scrubs, which occupy large areas of the interior, are a characteristic feature of Australia.
Water Courses.—The chief river is the Murray, which, with its affluents, the Murrumbidgee, Lachlan, and Darling, drains a great part of the interior W. of the Dividing Range, and falls into the sea on the S. coast (after entering Lake Alexandrine). Its greatest tributary is the Darling, which may even be regarded as the main stream. On the E. coast are the Hunter, Clarence, Brisbane, Fitzroy, and Burdekin; on the W. the Swan, Mur chison, Gascoyne, Ashburton, and De Grey; on the N. the Fitzroy, Victoria, Flinders, and Mitchell. The Australian rivers are of little service in facilitating internal communication. A considerable river of the interior is Cooper's Creek, or the Barcoo, which falls into Lake Eyre, one of a group of lakes on the S. side of the continent having no outlet, and, ac cordingly, salt. The principal of these are Lakes Eyre, Torrens, and Gairdner. Another large salt lake of little depth, Lake Amadeus, lies a little W. of the center of Australia.