The eastern side of the country is traversed by a great range of thinly timbered down, clothed with grasses and herbage, and rising to an elevation of 3500 feet. These are known as the Blue Mountains, and stretch from north to south over nearly thirty degrees of latitude, from Cape York to Cape Wilson. All their western slopes descend gradually towards the interior, until they are lost in the vast desert plain of the interior. The streams which flow in this direction either pour their waters into the great rivers, such as the Darling and the Murray, which has an internal navigation of 1800 miles, or lose themselves in the marshes and lakes, which the great summer heats periodically dry up. Another chain of mountains stretches from south to north along the western coast of Australia, from Point d'Entrecasteaux to Murchison River. A third chain, in the northern region, runs from east to west, between Camden Harbour and the Gulf of Carpentaria. The interior of the country is, as I have already indicated, in all probability an immense plain, thinly sown with trees of the two families of Acaciæ and Eucalypti, and tenanted by the wombat and the kangaroo. Over this vast portion of Australia, which still remains a blank upon the map, numerous expeditions of discovery have been attempted since the earliest days of European colonization. Hardy pioneers--those men who are the real, but obscure, and speedily forgotten founders of empires--have sacrificed their lives in the endeavour to lay down a track across the great island-continent from north to south. Anglo-Saxon enterprise no sooner found itself securely planted on the sea-coast, than it felt that behind it lay a continent to acquire, and the indomitable instinct of the race bade it continue its mission of colonization. During the last quarter of a century, the colonial governments have liberally encouraged these explorations, and the annals of Australian discovery have been illuminated by the names of Eyre (1840), Sturt (1845), Leichardt (1846-48), Kennedy (1848), and M'Douall Stuart (1858-62), second to none among our English discoverers in patience, resolution, and heroic daring. The problem remained: to cross the central wilderness of Australia, and prove the possibility of a passage from the southern shores to the northern, from Melbourne to the Gulf of Carpentaria. This problem was finally solved, at no light cost, by the intrepid Burke and energetic Wills. On the 20th of April 1860, there set out from Melbourne, under the auspices of the Government of Victoria, a small troop of gallant explorers, under the immediate direction of Robert O'Hara Burke, a man well-fitted for his post: born in the county of Galway in 1821, after having served as captain in a Hungarian regiment, he had discharged for several years the duties of inspector of a body of the colonial police.