To assert positively that we were on the margin of the lake, or sea, into which this great body of water is discharged, might reasonably be deemed a conclusion that has nothing but conjecture for its basis; but if an opinion may he hazarded from actual appearances, which our subsequent route tended more strongly to confirm, I feel confident we were in the immediate vicinity of an inland sea, most probably a shoal one, and gradually decreasing, or being filled up by the immense depositions from the waters flowing into it from the higher lands, which, on this singular continent, seem not to extend beyond a few hundred miles from the seacoast; as westward of these bounding ranges, (which from the observations I have been enabled to make, appear to me to run parallel to the direction of the coast), there is not a single hill or other eminence discoverable on this apparently boundless space, those isolated points excepted, on which we remained until the 28th of July; the rocks, and stones composing which, are a distinct species from those found on the above ranges.

I trust your excellency will believe, that fully impressed with the great importance of the question, as to the interior formation of this great country, I was anxiously solicitous to remove all ground for farther conjecture, by the most careful observations on the nature of the country; which though it was to me a proof that the interior was covered with water, yet I felt it my duty to leave no measure untried which would in any way tend to a direct elucidation of the fact.

It was physically impracticable to gain the edge of these waters by making a detour round the flooded portion of the country on the south-west side of the river, as we proved it to be a barren wet marsh, overrun with a species of polygonum, and not offering a single dry spot to which our course might be directed; and that there was no probability of finding any in that direction, I had a certain knowledge from the observations made during the former expedition.  To circle the flooded country to the north-east yet remained to be tried; and when on the 7th of July I returned to the tents, which I found pitched on the high land before mentioned, and from whence we could see mountains at the distance of eighty miles to the eastward, the country between being a perfect level, Mr. Evans was sent forward to explore the country to the north-east, that being the point on which I purposed to set forward.

On the 18th of July Mr. Evans returned, having been prevented from continuing on a north-east course beyond two day’s journey, by waters running north-easterly through high reeds, and which were most probably those of the Macquarie River; as during his absence it had swelled so considerably as entirely to surround us, coming within a few yards of the tent.  Mr. Evans afterwards proceeded more easterly, and, at a distance of fifty miles from the Macquarie River, crossed another much wider but not so deep, running to the north:  advancing still more easterly, he went nearly to the base of the mountains seen from the tent, and returning a more southerly route, found the country somewhat drier, but not in the least more elevated.