With respect to that part of its coast at which the rivers falling from the eastern mountains, discharge themselves, it is a question of very great doubt. It seems that Capt. King, in consequence of some peculiarities in the currents at its N.W. angle, supports Mr. Cunningham's opinion as to their probable discharge in that quarter. But I fear the internal structure of the continent is so low, as to preclude the hopes of any river reaching from one extremity of it to the other. A variety of local circumstances, as the contraction of a channel, a shoal sea, or numerous islands, influence currents generally, but more especially round so extensive a continent as that of which we are treating; nor does it strike me that any observations made by Capt. King during his survey, can be held to bear any connection with the eastern ranges, or their western waters. It may, however, be said, that as the course of the Darling is still involved in uncertainty, the question remains undecided; but it appears to me, the discovery of that river has set aside every conjecture (founded on previous observation) respecting the main features of the interior lying to the westward of the Blue Mountains. Both Mr. Oxley and Mr. Cunningham drew their conclusions from the appearances of the country they severally explored. The ground on which those theories were built, has been travelled over, and has not been found to realise them, but subsequent investigation has discovered to us a river, the dip of whose bed is to the S.W. We have every reason to believe that the sources of this river must be far to the northward of the most distant northerly point to which any survey has been made, as we are certain that it is far beyond the stretch of vision from the loftiest and most westerly of the barrier ranges; from which circumstance, it is evident that whatever disposition the streams descending from those ranges to the westward may show to hold a N.W. course more immediately at the base, the whole of the interior streams, from the Macquarie to the Dumaresq, are tributaries to the principal channel which conveys their united waters at right angles, if not still more opposite to the direction they were supposed to take, as far as is yet known. COURSE OF THE DARLING. The Darling River must be considered as the boundary line to all inland discoveries from the eastward. Any judgment or opinion of the interior to the westward of that stream, would be extremely premature and uncertain. There is not a single feature over it to guide or to strengthen either the one or the other. CHARACTER OF THE WESTERN INTERIOR.