July 20.--The morning was fine; and after much contrivance, we succeeded in taking with us whatever was essential to our future security, and the whole of the provisions except two casks or flour. The horses were, however, very heavily laden, carrying at least three hundred and fifty pounds each; a weight which I was fearful the description of country we had to pass over would render still more burthensome. We had, however, relinquished every thing that was not indispensable, and the saddle horses were equally laden with the others. Mount Harris, under which we had remained for the last fortnight, is in lat. 31. 18. S., long. 147. 31. E. and variation 7. 48. On the summit of the hill we buried a bottle, containing a written scheme of our purposed route and intentions, with some silver coin. Our course during the day was east by north, by compass, over a level country intersected with marshes, over which the horses travelled with the utmost difficulty, and not without repeated falls. Considering how heavily they were laden, I was unwilling to press them at this early period of our journey, and halted after going seven miles on the above course. From Mount Harris, bearings were taken to the most remarkable elevations in Arbuthnot's Range, as follows: Mount Exmouth, (northern extreme of the range) N. 79. E. Mount Harrison, (centre) N. 85. E. Vernon's Peake N. 88. E. July 21--Proceeded on the same course, through a country of alternate brush and marsh: whatever obstacles the former opposed to the progress of the horses, were nothing to the distress occasioned by the latter, in which they sank up to their knees at every step; I could not suffer them to proceed farther than seven miles, which, indeed, was not accomplished without severe labour. It is a singular feature in this remarkable country, that the botany and soil are in all respects the same as two hundred and fifty miles farther to the south-west, presenting nothing new to our researches. Passed a very large chain of ponds now running to the north-east, and named them Wallis's Ponds, after my friend, Captain Wallis, of the 46th regiment. July 22.--We passed over much the same country as yesterday, but having a large proportion of cypress forest. After travelling nearly ten miles, we halted on the edge of a very extensive flat, from three to four miles in diameter, covered with water. From this plain we had an excellent view of Arbuthnot's Range, which, from so low and level a country, appears of vast height. The horses failed much during the day, and several of them were severely wrung with their burthens.