AUSTRALIA, the s.w. division of Australasia. By some, it is strictly defined to be an island—as, indeed, may either of the masses of land called the old and the new worlds —while by others it is loosely described as a continent. It is bounded on the w. by the Indian ocean; on the n., by Torres strait; on the e., by th&Pacific; and on the s., by Bass's strait. It extends in s. lat. from 10° to :39°, and in e. long, from 113' to 134'; while its longest dimensions, as incidentally noticed under the head of AMERICA, may be said to run respectively on a meridian and a parallel. The parallel in question is that of about 25°, nearly the mean lat. of A. ; and the meridian is that of 142° or 143', nearly the mean long. of Australasia—a meridian, too, which, when produced in either direc tion, seems to mark out both Tasmania and Papua as geological continuations of Aus tralia. In English measure, the greatest breadth from n. to s. is upwards of 2000, and the greatest length from e. to w. nearly 2600 miles. Of the resulting rectangle of 5,200,000 sq.m., A. comprises more than a half, perhaps four sevenths, or, in all, about 2,970,000 sq.m.—half the area of South America, as the next larger conti nent, or ten times that of Borneo, as the next smaller island.
In the mutual relations of itself and the ocean—a point of vast importance to so large amass of land—A. is decidedly inferior to every one of the grand divisions of the globe. It is not indented by the sea, as is North America on the e., or Asia on the e. and s., or Europe on all sides but one. Again, as to navigable channels between the coast and the interior. A. is not to be compared even to Africa with its Nile and its Zambezi, its Niger and its Congo, its Gambia and its Senegal, and its many smaller arter ies of communication besides.
Among the indentations of the coast, the gulf of Carpentaria, on the the only one of considerable magnitude, does, it is true, penetrate inwards about 500 m. from cape York on the e., and about 400 from cape Arnhem on the west. This opening is entirely surrounded by tropical regions, rendered suitable for colonization by the fre quent and moderate rains. In connection with the construction of the overland electric telegraph from Adelaide, through the heart of the continent, to Port Darwin on the gulf of Carpentaria, distant 2000 in.—effected bY the government of South Australia, and opened in 1872—settlements have taken place in territories very different from what earlier observations seemed to indicate. For, saving the desert lying in the center in lat. 27' to 23° s., the interior of Australia is found to be covered with soil more or less fertile, in which, except during periodical droughts, that sometimes reduce the surface to a condition not unlike that of a beaten road, the rain-fall is sufficient to revive the dor mant germs of vegetable life, and to clothe the country with grass; while, occasionally, the fall of rain is so great as to transform the whole of a plain, as far as is visible, into a sea, on the disappearance of which, in a wonderfully short time, the ground becomes cov ered with verdure. The other inlets put together are scarcely equal in size to the gulf
of Carpentaria alone; while, strictly speaking, most of them are rather mere bends in the coast-line than actual arms of the ocean. Of the secondary inlets, the two that cut deep est into the land are the gulf of St. Vincent and Spencer gulf, in the south. Of har bors, properly socalled, there is a remarkable deficiency; and this deficiency is all the more important from the dangerous character of the reef-girt shores. As to fluvial com • munications between the coast and the interior, they can, with a single exception, hardly be said to exist at all. The interior and the coast are alike unfavorable to the produc tion and maintenance of regular and permanent streams. The interior—comprising the whole mass within a border of not more than 100 m. in average width, and repre senting, in proportional size, the plate of a mirror with the scantiest possible breadth of frame round it—sends, as a general rule, hardly any tribute the ocean. So far from possessing any reservoirs for the supply of rivers, its only large body of water, the brack ish pool or salt marsh, according to circumstances, of lake Torrens (q.v.), is the land locked receptacle of at least one of its principal streams. With the single exception of the Murray, and perhaps its southern affluents, even such inland water-courses as do con duct their surplus to the sea, lose each a huge proportion of its volume through evapo ration and absorption. With regard to the coast streams, again, the mountains, which form the dividing ridge, being, in general, only about 100 m. from the sea, the streams are for the most part, from their shortness, of comparatively insignificant size. This is more peculiarly the case on the s.—for the Murray, as flowing from the inner slope of tae maritime ridge, is no exception to the general rule. To the w. of the Glenelg. which empties itself into the Southern ocean, between capes Northumberland and Bridgewater, the coast, yields not a single river worthy of the name; while the entire line between Streaky bay and cape Arid—a stretch of 10' of long. on the Great Australian Bight—pours, inereaible as it may seem, not a single drop of fresh water into the South ern ocean.