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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 frequent and moderate rains. In connectiou 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 m.-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 25° 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 dormant 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 covered 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 deepest into the land are the gulf of St. Vincent and Spencer gulf, in the south. Of har. bors, properly so called, 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 production 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 representing, 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 to the ocean. So far from possessing any reservoirs for the supply of rivers, its only large body of water, the brackish pool or salt marsh, according to circumstances, of lake Torrens (q.v.), is the landlocked 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 conduct their surplus to the sea, lose each a large 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 8.—for the Murray, as flowing from the inner slope of the 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 Bridgewator, the coast yields not a single river worthy of the name; while the entire line between Streaky bay and cape Arid-à stretch of 10% of long. on the Great Australian Bight-pours, incredible as it may seem, not a single drop of fresh water into the Southern ocean.
But the poverty of Australian hydrography is aggravated by the singularities of the SO-styled “weatherology.” An alternation of more or less rainless and rainy periods is characteristic of the Australian skies. The rivers undergo a similar alternation of drought and flood, the one state being, within certain limits, almost as destructive as the other. Even in these inequalities there is great irregularity. During the period of drought, a river presents a succession of phases—a scanty, thcugh still regular stream; nearly stagnant ponds with a connecting thread of water between them; detached "water holes" in all the gradations of a constantly decreasing depth; moist pits that may yield their buried treasure to the spade; and, lastly, parched hollows where the labor of digging may be expended in vain. In the drought, for instance, from July, 1838, to Aug., 1839—during which “not a drop of rain fell in Sydney”-even the Murray, generally described as the only permanent river of any magnitude in the country, dwindled away into a chain of pools; and a recent explorer in western A. found on the bed of a large river-an affluent, if it may be so called, of the thoroughly broiled and baked Murchison—the indubitable footprints, then 3 years old, of preceding explorers. The flood, again, varies as widely, if not so definitely and gradually, as the drought. To select what may be regarded as an average instance from a list of the floods of the Hawkesbury in New South Wales: the torrent, at the end of July and beginning of Aug., 1808, rose to a height of 86 ft., or fully 50 above the edge of the bank, destroy. ing the uncut crops of the settlement, and sweeping away stacks of wheat and great quantities of stock of every description. More than 60 such visitations appear to have been ascertained and recorded within the historical period, now extending over 80 years, of wbich about a third occurred in winter, the remainder being distributed in not very unequal proportions between spring, summer, and autumn, and that without the exemp tion of any one of the twelve months of the year.
The rivers of the e. coast-the Brisbane, Richmond, Clarence, Macleay, Hastings, Manning, Hunter, Hawkesbury, and Shoalhaven-are, in general, towards their mouths. tidal streams, flowing between high banks through a comparatively level region. Some of those of Victoria—such as the Glenelg-spring from a moist and undulating tract of country; while most of the others rise among the lofty ranges and snowy peaks of the Australian Alps—the coldest section of the bordering mountains by reason both of their altitude and of their distance from the equator. They are subject to frequent freshets in winter, and are less eccentric than the other rivers of A. in general. To the w. of the Glenelg, as stated above, rivers may be said almost to disappear. South A. possesses only a few inconsiderable streams, and a number of usually dry torrent-courses; and as to the Great Bight, still further to the w., more than 500 m. of the coast have been already characterized as utterly waterless. To the w., again, of cape Arid, the coast presents only a few small lakes and inconsiderable water-courses, but nothing worthy of the name of river. On the w. side of A., the Swan river is by far the largest of the water-courses. Generally speaking, the whole of them are fed almost solely by the winter rains, many of them, during the dry season, either disappearing through a great part of their course, or dwindling into a series of detached pools. Along the remainder of the w. coast, no rivers worth notice have yet been discovered. Nor yet along the n.w. have any been found, excepting a few small ones towards Cambridge gulf. The rivers of this neighborhood much resemble in character those of the opposite angle in the colony of Victoria. They rise at no very great distance from the sea. Near their sources they are mere torrents; but in the lowlands their generally slow currents wind through fertile plains and valleys, which are subject to sudden and terrific inundations. In North A. are several comparatively considerable rivers—the Victoria, the Flinders, the Roper, and the Albert. They are wide streams, rising in the elevated region of the interior, and traversing a rugged country, which is often flooded. Lastly, along the n.e., the streams are distinguished by their length, a distinction which they owe to their being parallel with the coast. They are the Mitchell, Lynd, Burdekon, Mackenzie, Dawson, Fitzroy, Belyando, etc.; the whole of them, with the exception of the two last named, having been discovered by Dr. Leichhardt. To pass from the rivers of the coast to those of the interior, we must confine ourselves to two of the latter-Barcoo or Victoria, and the Murray with its numerous tributaries. The upper part of the Barcoo was first discovered by Sir T. Mitchell, in a broken district, lying 300 or 400 m. from the e. coast, and nearly on the tropic of Capricorn. Its broad reaches might there have floated a steamer. Since then, it has been traced by Mr. Gregory through a solitary course into lake Torrens, though, in point of fact, it is only from time to time that it actually has a surplus to pour into its receptacle. The system, again, of the Murray and its tributaries is vastly more complex. Rising on the w. or inner slope of the Australian Alps, it flows to the w.n.w. with a plentiful stream, which alone in the country, after the fashion of a tropical river, rises and falls regularly according to the season; and, though inacessible to ships of any size from the sea, it has an internal navigation of about 2000 m. in length. On its left or southern side, it receives several considerable streams, such as the Ovens and the Goulburn. But it is on the right or northern side that the basin of the Murray is most peculiar. The principal affluents in this direction are the Murrumbidgee and the Darling. The Murrumbidgee, to which the Lachlan, only less “mysterious" than the Darling, contributes such surplus as it from time to time may have, forms the chief strand of a complicated net-work of water-courses. The Darling, after it has received all its tributaries, pursues its lonely way for 660 m., sending off branch after branch to lose themselves in landlocked lagoons. Nor is its growth less curious than its lower channel. The whole of the interior drainage of the maritime ridge of New South Wales between lat. 25° and lat. 34', a stretch of about 625 m., converges into a vast basin of clay, on the 30th parallel, where the Balonne, Dumaresque, Gwydir, Namoi, Castlereagh, Macquarie, and Bogan, after spreading out in spacious marshes, and amid complicated junctions and bifurcations, unite such surpluses as absorption and evaporation may have left them to form the “mysterious" Darling.
Such being the hydrography of A., the investigation of the interior, so far as it has hitherto advanced, has been conducted almost entirely by land. In 1844, Sturt penetrated to the center of the country, between Spencer gulf on the s., and the gulf of Carpentaria on the n., meeting sterility and drought. In 1847, Leichhardt, encouraged by the success of his previous expedition from Sydney to Port Essington, started from Moreton bay on the e., for western A., following a sort of diagonal of nearly the greatest possible length; and, as was to be dreaded, he must have failed in his bold enterprise; for neither of himself nor of his companions has any intelligence ever been received. Subsequent explorations made by Stuart (1858–62), Burke and Wills (1860–61), and by expeditions in search of them, have resulted in the discovery that this interior of the Australian continent is, on the whole, well fitted for pastoral, and, in many places, for agricultural purposes. See AUSTRALIAN EXPLORATIONS. Any detailed view of the climate, besides being equally difficult and unsatisfactory with respect to so vast an aggregate of latitudes and longitudes, has been rendered comparatively unnecessary by the incidental allusions to the subject in the preceding paragraphs. The following are tabular statements extracted from local publications:
MEAN ANNUAL RAIN-FALL.
Latitude. Rain-fall Brisbane, Queensland, lately Moreton bay................. 27° 1' 35.92 in. Port Macquarie, New South Wales.
31° 25' 70.79" Sydney, New South Wales........
33° 51' 49.00 « Port Phillip, Victoria Colony ...
38° 18' 29.16 “ Lake Alexandrina, mouth of the Murray......
17.45 " Adelaide, South Australia..............................
34° 55' York, West Australia. ......
Whole year. .....
143 The mean temperature of Melbourne is 59°, being about 9° higher than that of Lon don. The warmest month is Jan., the mean of which is 68'; the coldest is July, 29.34. The corresponding temperatures of London are 63° and 36o.
Geology.-The little that is yet known of the geology of A. has been chiefly obtained from occasional notes scattered through the journals of scientitic travelers. So utterly unknown were the mineral treasures of this continent, that it was only comparatively lately, and by the merest accident, that the Burra Burra copper-mines were discovered. In 1851, farmers were turning up with the plow the auriferous alluvium; pebbles of gold-bearing quartz were used for garden-walks; and we have heard of an Oxford graduate who ornamented his garden-walls by building into them masses of white quartz variegated with portions of the unrecognized yellow metal. In 1846, when count Strelecki submitted to Sir R. Murchison a series of rock and mineral specimens gathered in southern A., the practiced eye of that veteran in geology recognized in them a remarkable resemblance to the rocks in the auriferous districts of the Cral mountains, which he had thoroughly explored. He could not ascertain that gold had ever been found in the colony, but so certain was he that the precious metal existed, that ho printed and circulated amongst the miners of Cornwall a paper urging them to emigrate to New South Wales, and seek there for gold, as they had been accustomed to seek for tin and zinc among the alluvial débris of their own hills. After a few years, in the researches of Mr. Hargreaves, and the diggings that followed, this remarkable prediction was fulfilled to an extent that could not have been anticipated. This narrative is of much value, as showing that geology is no longer in the hands of empirics; that its truths have been so gathered and arranged as to afford bases for safe inductions; and that, when rightly used, this science is of the first importance, even when tested by the utilitarian Cui bono? of the age. Recognizing this, the colonial governments of A. have appointed state geologists, who have begun their examination of the Australian continent, and have published several reports.
In looking at the continent as a whole, it will require not many broad touches to convey all that is at present known. An immense, roughly quadrangular and comparatively flat district in central A., extending from the southern shores in lat 33° s., where it forms a coast-line of somewhat bold cliffs, to 18° s. lat., and having for its eastern and western limits 124° and 138° e. long., is composed of tertiary rocks. The superficial characteristics of this vast almost unpeopled tract have already been described. Nothing more is known regarding its structure. Three other patches oï tertiary rocks exist. The largest is a broadish tract, which forms the coast of western A. northwards from the colony of Perth, as far as the tropic of Capricorn. The second occupies a considerable portion of the valley of the Murray river, in that district known as lower Darling. The last and smallest patch covers the southern slope of the Australian Alps, extending along the shore from Wilson's promontory to cape Howe.
The immense central expanse of tertiary beds is surrounded by a continuous belt of plutonic and metamorphic rocks, only broken on the southern shores, where it forms the coast-line, and where the sea has indented it, forming in bay which has for its boundaries the more enduring primitive rocks. This crystalline belt is, on its e., n., and western sides, separated from the sea by a tract of land having a nearly equal breadth of 100 m. throughout its course. Tracing this from its southern termination in western A., we find a limited region of palæozoic rocks occupying the colonized district around Perth, and containing valuable coal-beds. Northwards, as already indicated, the coastline consists of tertiary rocks. From their termination in lat. 237, S., the rocks along the whole western and northern shores are composed of secondary strata. On the eastern shore, from cape York to the western boundary of Victoria, the formations belong to one or other of the primary series. Through the whole extent of this boundary tract, whether consisting of tertiary, secondary, or primary strata, numerous and often extensive patches of igneous rocks exist which have been erupted during the tertiary or post-tertiary epochs.
About 100 m. from the bounding tract of palæozoic rocks on the eastern limits of A.. and running parallel with it, there is an equally broad strip of similar strata extending from the shores of the gulf of Carpentaria to Bass's strait. These two regions, which unite together and are largely developed in the southern portion of Victoria, supply the great store of Australian mineral wealth. The veins which intersect these strata were the original matrices of the gold. It has not, to any extent, been sought for in this, its original position, from a belief that the amount of metal decreases as we descend in the solid rock. Mr. Selwyn, colonial geologist for Victoria, has, however, lately reported in favor of quarrying for the gold in the solid rock. The greatest amount of gold is found in the heaps of débris or old alluvium derived from the denudation of the old slaty rocks. The auriferous rocks of eastern A. are lower silurian, as shown by Messrs. Lonsdale and Salter, from the examination of specimens of pentameri, trilobites, and corals from the strata which overlie them. Mr. Selwyn has referred the Victoria gold. bearing strata to the same age, from the occurrence in them of about 60 species of lower silurian fossils, including trilobites, graptolites, and lingulæ. The auriferous quartzose veins are most abunrlant in the vicinity of eruptive rocks, whether granite, porphyry, or greenstone.
Messrs. Selwyn and Rosales have shown that the superficial drifts containing the gold consist of three distinct stages. The lowest or oldest contains the remains of wood and seed vessels differing little from the present vegetation; among them the cones of banksia, an exclusively Australian genus, have been identified. The remains of animals exhibit also the representatives of the living fauna of the country. Gigantic marsupials then existed-kangaroos, potoroos, and wombats-representing the elephants, and even the large carnivora of Asia; but with the exception of the mastodon, of which one species has been found in A., there were, it would seem, no generic forms common to this great district and the rest of the land in the eastern hemisphere. In Victoria, these beds of alluvium have been overflowed and even interlaced by basaltic coulées, which evidently proceeded from terrestrial volcanoes, inasmuch as the vegetable matter beneath them has been charred and destroyed in situ by the eruption.
An extensive coal-field has been known for some time as occupying the whole of the great basin of the Hunter river and its tributaries, down to the sea-coast at Newcastle, where several beds crop out on the beach. For a good many years, the monopoly held by the Australian Agricultural Company, in the working of the coal, has ceased to exist, and as the result, the trade has increased enormously. From Port Hunter the coal is dispatched to all parts of A., and even to New Zealand and California. Beds belonging to the carboniferous system have been discovered also in western A., near Perth, and the coal has been successfully, though not so extensively wrought there.
After gold and coal, the next most important Australian mineral is copper. The Burra Burra mines, in South A., were discovered in 1842. The lode is 17 ft. wide, and of vast extent. The ore contains 75 per cent of metal, and is quarried out like stone in immense masses. Copper has also been wrought for several years at Bathurst, in New South Wales. The poorest ores are here most abundant, the rich pyrites existing only in small quantity. Copper is now mined and smelted in western Australia.
Iron is spread in great profusion over all the continent. To such an extent does it exist in several of the mountains on the north coast, that they violently affect the magnetic needle. At Berrima, in New South Wales, an oxidulated iron ore, from which is manufactured a good steel, nas been worked, but not successfully. Iron has been noticed in quantity in both southern and western Australia.
Lead is most abundant e. and s.e. from Adelaide, at Mt. Beevor, and near cape Jervis. The ore of Glen Osmond mines, near Adelaide, yields 75 per cent of lead, besides a proportion of silver. This metal is also wrought at Geraldine, in western Australia.
Manganese, bismuth, tin, and antimony have been met with in South A., as also good specimens of jasper, chalcedony, and opal.
Zinc and quicksilver are mentioned as occurring in western Australia.
Botany and Zoology.—The natural history of A. is remarkably different from that of any other quarter of the globe. Its trees-which seldom for dense forests, but are scattered as in a lawn or park, where the colonist finds pasture for his flocks without any previous clearing-are, almost without exception, of very peculiar appearance. Among the largest of them are species of eucalyptus (q. v.), some of which attain the height of 150 or 200 ft., rising without branches to at least half their height, their stately stems resembling beautiful columns. Some of the eucalypti, on account of their resinous exudations, are known to the colonists as gum-trees. Their leaves are leathery. It is, indeed, a general characteristic of the trees and shrubs of A., that their leaves are evergreen and of a firm texture; and although in this a beautiful adaptation may be perceived to the prevailing dryness of the climate, the foliage wants the delicacy and the liveliness of tints which in other countries form so much the charm of the landscape. The casuarina (see CASUARINA) or cassowary-trees (beef-wood, she-oak, swamp-oak, etc.), among which, as among the eucalypti, are some of the largest and most useful timber-trees, are still more singular in appearance; their long, wiry, jointed branchlets, which greatly resemble those of equiseta, are quite leafless, having only very small sheaths instead of leaves. Equally destitute of foliage are the greater number of the acacias (q.v.), whicle abound in the Australian flora. The abundance of proteacea