242 macculloch's range. [ch. v. 



the edging of stiff clay, always to be found near the base of 

 the red sand hills, which form the limits of those softer 

 plains that usually extend for several miles back from the 

 river. On ascending the highest of the hills on my left, I 

 discovered, that the ground to the southward was much more 

 broken, and the appearance of a valley between me and a 

 range, which I named after Dr. Macculloch, raised my hopes of 

 finding some change in the country. On ascending, however, 

 another eminence to the right, I perceived the summit of a 

 hill, which bore west-north-west, and rather discouraged 

 my hopes respecting the river, for I had assumed that its 

 new direction towards the westward would continue. We 

 crossed the hill, and encamped about two miles to the south- 

 ward of a bend of the river. Here, there was a fall of about 

 four feet over masses of ferruginous clay, with selenites em- 

 bedded.* The banks were lower at this point than usual, 

 and the quantity of running water was rather increased, pro- 

 bably from the springs, which we had latterly observed in 

 great abundance in the banks, generally about two feet above 

 the surface of the stream. On the plains, this day, we found 

 much selenite. 



June 25. — There was again a considerable mirage or re- 

 fraction this morning, on the rising of the frost ; and I has- 

 tened to a small hill, near our camp, that I might behold 

 the transient vision of a distant horizon. The view was most 

 interesting, for the high lands on all sides, appeared raised 

 as if by magic ; and I thus discovered, that the hill, previ- 

 ously seen in the west, was connected with a chain, which 

 extended round to the north, and that there was higher 

 land to the southward of Macculloch's range ; the highest 

 point being to the east, or east-north-east, beyond the hill 

 discovered on the 21st instant. The horizon was lowest to- 

 wards the west-south-west, for even in the south-west, I could 

 perceive a rise, sufiicient to confine the course of the river 

 to the west-south-west. We proceeded nearly west by south, 



• This clay, in the opinion of geologists, has every appearance of a mud 

 deposit. 



