130 AUSTRALIA the western ; and on the northern, the Vic- toria, Alligator, Roper, and Flinders. The lakes of Australia consist, during the greater part of the year, of swamps full of weeds and grass, or of mere heds of mud or sand. This applies even to the largest inland bodies of water yet discovered, which lie grouped to- f ether near the centre of the 8. coast, N. of pencer gulf. Here is Lake Torrens, ahout 140 m. in length, hut very narrow, lying about 40 m. from the head of the gulf; and 50 m. further N., Eyre lake, still larger. E. of this is Lake Gregory, which might be more correctly called Gregory lakes, since it is divided into nu- merous parts, between which no considerable communication has been discovered. TV. of Lake Torrens lies the extensive Lake Gairdner, and E. of it Lake Frome. The water of this group of lakes contains a large proportion of salt, and salt also abounds in the marshes and innumera- ble swampy ponds which lie in this region. The geological structure of Australia has not been thoroughly ascertained. It appears, how- ever, that the main table land rests on terti- ary sandstone, directly overlying the primary rocks, the fact that no traces of a secondary formation have been found forming one of the most remarkable features of Australian geol- ogy. The mountains rising from the table land in the interior ace, on the contrary, gen- erally of volcanic structure. In the range of the 8. W. coast primary rocks are most prominent granite, syenite, &c. ; and all the greater coast ranges probably resemble these. In several of the great valleys in the S. E. part is found a limestone containing numerous fossils. Bituminous coal is abundant near Newcastle at the mouth of Hunter river in the eastern part of New South Wales, and large mines are already worked there. Rich deposits of copper are also found at Burra-Burra, Wallaroo, and Ka- punda in South Australia that at Burra-Bur- ra being probably the richest in the world. The famous gold fields are in the Bathurst dis- trict and the N. W. part of Victoria. Every indication shows that only in the latest geo- logical period has Australia risen from the sea. The recent deposits following directly on the primary rocks, the salt lakes, the whole con- struction of the continent, indicate this; and geologists affirm that the southern coast is still in process of imperceptible but constant up- heaval. The climate of Australia is exceed- ingly hot, but dry and healthy in such southern parts as are already colonized, where it appears favorable to European constitutions, and re- sembles in many particulars the climate of Spain. In the extreme north, beyond the tro- pic of Capricorn, which crosses the continent near its centre, the heat is more oppressive, and the absence of large streams gives almost the arid climate of a desert. Here, however, the tropical rainy season brings relief with un- failing regularity, lasting from November till April; while in the south the rains, though of tropical violence, are irregular, occurring at intervals between March and September, and often leaving the country exposed to long droughts. There appears to be almost no rain in certain portions of the central continent, and these have become deserts, from which bot winds blow toward the coast, carrying clouds of sand. Extraordinary variations of temperature are among the most remarkable phenomena of the country. Falls in the mer- cury of 20 to 30 F. in half an hour are com- mon on the coast, especially in the summer; and comparing the reading of the thermometer in the sun at noon with the same at midnight, a variation of 99 in the 12 hours has been observed. The average height of the ther- mometer for the year on the N. coast is about 80 ; at Port Macquarie on the E. coast, 68 ; at Port Jackson (Sydney), 66 ; at Melbourne, on the S. coast, 61 ; at Perth, on the TV. coast, 64. In summer, however, the mercury often rises to 100, or even 120. One traveller (William Howitt) has even stated his experi- ence at 139. The animals of Australia are peculiar, not less in themselves than in their distribution. The carnivora are few, and the only really destructive beast of prey is the dingo, an animal in size between a fox and a wolf, and resembling a dog. The dingoes roam about in packs and attack sheep, killing and wounding many, but eating few. Ruminating animals and pachyderms are unknown. But while Australia is thus deficient in the classes of animals most abundant in other parts of the world, its fauna consists very largely of a class elsewhere but sparingly represented the mar- supialia or pouched animals. Of these the largest and perhaps the most common is the kangaroo. A smaller species of this animal is called the wallaby. The opossum, the petau- rus or flying opossum, and the dasyurus (a car- nivorous pouched animal) are the other species most frequently met with. Another peculiar family inhabiting Australia are the monotre- mata, including the two curious species echid- na, or porcupine ant-eater, and ornithorhyn- ehiw. The latter species is a water animal shaped like a beaver, but has web feet, a bill like that of a duck, and in the case of the male spurs upon the hind feet. (See MONO- TEEMATA.) There arefive species of rodents, four small and insignificant, and one somewhat larger and resembling the beaver in its habits. The birds include several of the largest species of eagles, falcons, and owls. Parrots of the most brilliant plumage, birds of paradise, and orioles are abundant ; while among the pecu- liar birds are the emu, the black swan, the ibis, and the "laughing jackass" or "bushman's clock," a large kingfisher, with a remarkable voice. The marine animals include the dngong, found along the northern shore between More- ton bay and Cape York. Sharks abound on all the coasts. The amphibious animals are few and small. Few of the serpents are ven- omous, and none are of great size. The in- sects, however, include several species whose
