No question in geography has presented a wider field for conjecture than the much-debated one of the nature of the interior of Australia. Is it desert, or water, or pasture? inhabited, or destitute alike of animal and vegetable life? The explorations of Captain Sturt, and the journey of Mr. Eyre, would incline us to believe that the country is one vast sterile waste; but the journey of the latter is worth nothing as an attempt to expose the nature of the interior, since he never left the coast. It certainly shows how much suffering the human frame can endure; and whilst, as illustrative of Australian geography, it is valueless, it is highly creditable to the energies of the traveller. The expedition of Captain Sturt has shown that to the north of South Australia the country is chiefly desert, totally incapable of supporting animal life: while the geological specimens of that traveller prove that the rich mineral strata of South Australia extend far beyond the pastoral boundaries of the colony. A reference to the journey of Mr. Lefroy and myself, from York to the south-east, will show that there exists a low level country running far beyond our farthest eastern point, which may afford abundance of water and pasture for any future expedition proceeding in that direction. An expedition starting from these lakes in the BEGINNING OF WINTER, so as to take advantage of the first supplies of water, might advance far enough into the interior to discover at least the possibility of proceeding before the succeeding summer would render it impossible to return; for the lakes alone would not be sufficient to ensure a supply of good drinkable water during the summer, as they generally become quite salt long before summer is over. It would be necessary to find a good deep water-hole for the party to remain at during the dry season, and from which they could push out small lateral expeditions as a sort of foundation for the next season's main advance. Expeditions in Australia require great circumspection. It is not the most rapid traveller who will get the farthest, but the most prudent and cautious. I consider it quite possible to get across the island, either to South Australia or to Port Essington. Most probably it would be easier to get to the latter than the former.