Page:Encyclopædia Britannica, Ninth Edition, v. 23.djvu/85

Rh are the Great Lake (50 miles in circuit), Sorell, St Clair, Crescent, and Echo. The colony is divided into eighteen counties. The principal towns are Hobart, the capital, on the Derwent, with a population of 21,118 in 1881 (25,044: in 1886), and Launceston (12,752 in 1881; 19,379 in 1886), at the head of the Tamar. The rugged western half of the island has only a few small settlements, while the eastern country is increasing in population on account of the mines.

Climate,—This small colony has a far greater range of climate than can be experienced throughout the Australian continent. The eastern side is dry ; the western is very wet. Tin and gold miners are partially arrested in their work during summer from want of water in the north-east. Dense forests and impracticable scrubs result in the west from deposition of a hundred or more inches of rain in the year, while other parts to the east occasionally suffer from drought. Tasmania does not escape the summer visit of an Australian hot wind. Hobart and Launceston, being near the sea, have greater equability of temperature, with rare frosts. The mean temperature of Hobart is 54°, of Waratah in the north-west 44°. Hobart averages 22 inches of rain, less than Melbourne, Sydney, and Brisbane. Inland, in the settled parts, cold is severe in winter, but only for a short period. The wooded north-west shore has no cold and no excessive heat, but plenty of showers. Up in the lake country the climate rather resembles the Highlands of Scotland. On the west and southern coasts the winds are usually strong, and often tempestuous.

Like New Zealand, Tasmania is very healthy. No miasma is retained in its forests. Bheumatism and colds may prevail, but little fever or dysentery occurs. Perhaps no part of the world can show relatively so many aged people. Children generally display the robustness of English village life. As a retreat for Australians, Tasmania in the summer has strong claims. Cool and strengthening airs, magnificent forest solitudes, and secluded fern-tree vales may be enjoyed along with all the comforts of modern civilization.

Geology,—The comparatively recent connexion of Tasmania with Victoria is evidenced not less by rocks than by flora and fauna. The granitic islands of Bass's Strait are as so many stepping-stones across, a depression having converted the loftier districts into islands. The want of similarity, however, between the tufted-haired Tasmanians and their Australian neighbours would indicate that the disruption took place before the advent of the younger race on the northern sid^. While doubts exist as to the presence of rocks older than the Silurian, a Palaeozoic floor exists north, east, south, and west, though often thrown up into irregular ranges, sometimes over 5000 feet, by igneous irruptions. Convulsions have distinguished the history of the little island from one end to the other. Not only is granite in all its varieties very prevalent, but there is an immense amount of metamorphism in different directions. Then, at another period, not merely porphyries, but basalts and greenstones, were widespread in their ravages. They consumed or deranged beds of coal, and overflowed enormous tracts. Earthquakes were busy, and tremendous deluges denuded great areas to depths of thousands of feet, leaving mountains of Primary rock, with peaked or plateau summits of basalt or greenstone. There are prismatic walls several hundreds of feet in height, and 4000 feet above the sea-level, as at Mount Wellington, looking down upon “ ploughed fields ” of greenstone blocks. Still, unlike Victoria, there are not the extinct craters t'© tell the tale of more modern lava flows. The lake district, up to over 4000 feet, is a tangled mass of granitic and metamorphic rocks. Quartz is so common a feature that the western storm-bound cliffs reflect a whit© light to passing ships; while, mica, talcose, dolerite, and siliceous schists are common over the island. Contorted slate and the tesselated pavement of Tasman’s Peninsula are effects of that transmuting period. Granite is strong at eastern and northern points, at western localities, in the interior, and in the straits. Greenstone is exhibited southward in enormous fields, as well as in the western and lake districts, and alternates often with basalt. Silicified trees are seen standing upright in the floor of igneous rock. The Prim- ary rocks have more casts of former life than fossils in ordinary condition. The Hobart clay-slate abounds in Fenestella or lace coral, and trilobites occur in limestone. Slate is abundant on the north-west coast, the South Esk, and westward. New Bed Sandstone near Hobart is marked by the presence of salt- beds. The Carboniferous formations are not much exhibited on the western half of the island, but are prominent along the Mersey and other northern rivers. The southern fields are torn by igneous invaders. Anthracitic forms are conspicuous on Tasman's Peninsula. Inland, on the eastern side, the formations spread from near Hobart northward for scores of miles, and ev'en to a thousand feet in thickness. The Eingal and Ben Lomond north-eastern districts are remarkably favoured with Carboniferous sandstones and crinoidal limestones, bearing excellent seams, and like strata are noticed in islands off the east coast. Carbonaceous non-coal-bearing beds by the Mersey are 500 feet thick. Tertiary rocks are not extensive, save in the breccia and coarse sandstone south of Launceston, over Norfolk plains, and along some river valleys. Alluvial gold deposits belong mainly to the Pliocene formations, — the ancient Primaries containing the auriferous quartz veins. Greenstone and basalt belong to various periods, the latter being specially apparent in the Tertiary epoch. Travertine, near Hobart and Richmond, is from freshwater action. The Pleistocene development was characterized by overwhelming denuding forces. Raised beaches are noticed along some of the larger rivers, and westerly moraines would imply a greater elevation of the country formerly. Caves and recent beds exhibit marsupial forms analogous to existing ones. Not far from Deloraine are limestone caves, with passages two miles in extent. The density and intricacy of the island scrubs have interfered with the investigation of its geology.

Minerals.—Tasmania has failed to take a very important position as a gold producer. Still, when the crushing of 1300 tons in one mine produced 0611,538, adventurers may wtill be hopeful. From Beaconsfield mine, west of the Tamar, gold was obtained to the value of £615,330 from July 1878 to January 1, 1887. In 1885 there were five districts under commissioners of mines. Westward, gold is found from Arthur river to Point Hibbs; north-westward, from Blyth river to Cape Grim. In the north-east are Scottsdale, Ringarooma, Mount Victoria, and 'Waterhouse fields; east, Fingal and St George river. Arsenic and silver are found with gold in the north-east; and iron, arsenic, copper, and lead with it at Beaconsfield. For 1885 the gold export was 37,498 oz., worth £141,319. Silver occurs at Penguin, lilount Ramsey, and aratali (Mount Bischoff), combined with lead. Copper is met with at Mount Maurice, &c., but not in paying quantities. Bismuth at Mount Ramsey is rich, but the country is difficult to reach. Antimony, zinc, manganese, copper, plumbago, and galena are known west of the Tamar, where also asbestos in serpentine hills is plentiful. Tin is well distributed iu Tasmanian granite. Afount Bischoff, in tho scrubby, rocky, damp west, has the richest lodes; other mines are in the north-east and west. In ten years the product came to two and a half million pounds sterling. Bischoff district in 1885 gave 2871 tons of ore, much being found in huge blocks. Want of water in the north-east prevents much hydraulic working. Anthracite coal is pretty abundant at Port Arthur. Near Hobart are workings of poor quality. Around Ben Lomond are bituminous seams, but difficult of access. Fingal district has coal equal to that of Newcastle, with a seam of 14 feet, hut carriage is difficult. Mersey river coal mines yielded 60,000 tons in the course of over a dozen years. Iron was worked hear the Tamar, but did not pay, excess of chromium making it brittle; its steel was very malleable. All varieties of iron ores are known. Hobart freestone is largely exported to other colonies. Tasmanite or dysodile in the Mersey district is an inflammable resinous substance. During 1884 there

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