The interior of Australia is, as is well-known, an immense plain, having an average height of fifteen hundred to two thousand feet, with a decided tilt, or slope, towards the south-west. Round the foot of this tableland, is a terrace of lower country, varying greatly in width. The river systems of the coastal lands, lying between the sea and the foot of the tableland, were easily understood and traced, that of the interior was far more difficult. Starting from Cape York, in the extreme north, and following down the eastern coast, the edge of the tableland is formed of ranges, often of considerable height, the gullies and spurs of which are mostly clothed with scrub and jungle of tropical growth and luxuriance; amongst the peaks of this range there are Distant Peak, 3,573 feet; Pieter Botte Mountain, 3,311 feet; Grey Peak, 3,357 feet; and the Bellender Kerr Hills, 5,433 feet high. Further south, the level is more uniform; the isolated peak of Mount Elliott--which attains a height Of 4,075 feet--forming the exception, until further south again the elevations approach to 4,250 feet. An average height of a little over two thousand feet is then maintained until the border line of Queensland is reached, and here--in Mount Lindesay--5,500 feet is met with. The New England Range maintains this altitude in many peaks, including Mount Seaview--from which point Oxley sighted the ocean-6,000 feet high. Still to the south, the mountains on the border of the plateau keep up an average of between three and four thousand feet until, at the south-east extremity of our continent, the greatest height is attained in Mount Kosciusko, falling some 700 feet short of the limit of perpetual snow, its elevation being 7,308 feet. To the westward, many of the peaks reach altitudes of over 5,000 and 6,000 feet, until the large depression is encountered through which the great body of interior waters find their way to the sea by means of the Murray Channel. West of this gap, the edge of the tableland is broken, and depressed, the highest crests of the coastal range rarely reaching to 3,000 feet in height, and along the shore line, facing the Great Australian Bight, it is almost non-existent. On reaching the south-west corner of Australia, the elevated edge reforms in the Russell and Darling Ranges, and trending northward, skirting the coast, culminates in Mount Bruce, 4,000 feet above sea level. From hence, the range following the sea line is broken, rugged and precipitous, but of inconsiderable height, and when the centre of the Gulf of Carpentaria is reached, it falls away into highlands and slopes, joining the eastern ranges. On the great plateau encircled by this range, no elevations of any moment are to be found; a kind of chain traverses the centre from north to south, but though in places presenting a bold formation, the highest altitude attained is in the Macdonnell Ranges--4,000 feet.