Crossing some stony ridges, we followed the party up the large watercourse, which I had traced so far on the 5th of August, since named the Burr, after the Deputy Surveyor-general of the colony, and at nineteen miles halted early in the afternoon, at some springs rising among rocks and rushes in its bed.  The water was very brackish, though drinkable, but did not extend far on either side of the spot we were encamped at, and when after dinner, I took a long walk up the watercourse to search for more, I was unable to find any either in the main channel or its branches.  The grass was abundant and good.  The latitude of the camp I ascertained to be 30 degrees 27 minutes S.

August 27.—­Having risen and breakfasted very early, I took Mr. Scott and a native boy with me, and steered for a very high hill with rather a rounded summit, bearing from our camp E. 17 degrees S. This I named Mount Serle, in accordance with a request made to me before my departure, by the Governor, that I would name some remarkable feature in the country after Mr. Serle.  This was the most prominent object we had hitherto met with; among high ranges it appeared the highest, and from a height above our present encampment, it had been selected by us as the most likely point from which to obtain a view to the eastward.

The elevation of this hill could not be less than three thousand feet above the level of the sea; but unfortunately, the injury my barometer had sustained in the escape of some of the mercury, and my being unable to fill it again properly, quite precluded me from ascertaining the height with accuracy.

In our route to Mount Serle, we observed another hill rather more to the northward, seemingly of as great an altitude as Mount Serle itself; this was not situate in the Mount Serle range, nor had it been seen by us in our view from the height above the depot.

At ten miles from our camp, we came to a large watercourse, emanating from the Mount Serle range on the south side, and running close under its western aspect, with an abundance of excellent clear water in it.  This I named the Frome, after the Surveyor-general of the colony, to whose kindness I was so much indebted in preparing my outfit and for the loan of instruments for the use of the expedition.

Having watered our horses we tied them up to some trees, and commenced the ascent of Mount Serle on foot.  The day was exceedingly hot, and we found our task a much harder one than we had anticipated, being compelled to wind up and down several steep and rugged ridges before we could reach the main one.

At length, however, having overcome all difficulties we stood upon the summit of the mountain.  Our view was then extensive and final.  At one glance I saw the realization of my worst forebodings; and the termination of the expedition of which I had the command.  Lake Torrens now faced us to the east, whilst on every side we were hemmed in by a barrier which we could never hope to pass.  Our toils and labours and privations, had all been endured to no purpose; and the only alternative left us would be to return, disappointed and baffled.