and the wishes of the Secretary of State, I was to keep on the 138th meridian (that of Mount Arden) until I should reach the supposed chain of mountains, the existence of which it was the object of Lord Stanley to ascertain, or until I was turned aside from it by some impracticable object.  Lake Torrens being due north of Mount Arden would, if I had taken that line, have been direct in my way, and I should have had to turn either its eastern or its western flank.  The Surveyor-General, Captain Frome, had tried the former, but although he went considerably to the eastward into the low and desert interior before he turned northwards, he still found himself entangled in that sandy basin, so that it appeared to me that I should do little more than clear it on the course I proposed to take.

As the reader, however, will learn in the perusal of these pages, I was wholly disappointed in the character of the Williorara.  Where that channel joins the Darling, the upward course of that river is to the north-east; and as that was a course directly opposite to the one I felt myself bound to take, I abandoned it and took at once to the hills.  At my Depot Prison, in lat. 29 degrees 40 minutes, and in long. 141 degrees 30 minutes E., I hoped that we had sufficiently cleared the north-east limit of Lake Torrens; but when on the fall of rain we resumed our labours, we measured 131 3/4 miles with the chain before we arrived on the shore of a vast sandy basin, which I could not cross, and to the northward of which I could not penetrate.  Thus disappointed in my attempt to gain the 138th meridian on a westerly course, as well as in my anticipation of finding Lake Torrens connected with some more central feature, it appeared to me that I could not follow out my instructions better than by attempting to penetrate towards the centre of the continent on a north-west course, for it was clear that if there were any ranges or any mountain chains traversing the interior from north-east to south-west I should undoubtedly strike them; but that if no such chains existed the proposed course would take me to the Tropic on the meridian of 138 degrees, and would enable me to determine the character of the interior, and more central regions of the continent.  In this attempt I succeeded in gaining the desired meridian, but failed in reaching the Tropic.  My position was about 500 miles north of Mount Arden, 60 miles from the Tropic, and somewhat less than 150 to the eastward of the centre of the Australian continent.  Forced back to my depot a second time, from the total failure both of water and grass, in the quarter to which I had penetrated with the above objects in view, having passed the centre in point of latitude, I again left it on a due north course to ascertain if there were any ranges or hills between my position and the Gulf of Carpentaria, as well as to satisfy myself as to the character and extent of a stony desert I had crossed on my last excursion.  That iron region