north, passed through vast openings, both to the eastward and westward of the province of South Australia, it as necessarily follows, that that province must also have been an island. I hope it will be understood that I started with the supposition that the continent of Australia was formerly an archipelago of islands, but that some convulsion, by which the central land has been raised, has caused the changes I have suggested. It was still a matter of conjecture what the real character of Central Australia really was, for its depths had been but superficially explored before my recent attempt. My own opinion, when I commenced my last expedition, inclined me to the belief, and perhaps this opinion was fostered by the hope that such would prove to be the case, as well as by the reports of the distant natives, which invariably went to confirm it, that the interior was occupied by a sea of greater or less extent, and very probably by large tracts of desert country.