The horses had shown an unusual desire to stray during the night, and as we had reason to apprehend a visit from the blacks, they were kept close to the camp; at 6.20 a.m. steered south-east, crossing a tableland about 250 feet above the camp, and at 8.0 a.m. descended by a rocky gully, in which was a fine spring, into a grassy valley, which varied from a few yards to a mile in breadth, bounded by sandstone hills, the strata of which were not well defined, but appeared to have a considerable dip to the west-south-west; in the upper part of the valley the creek was well supplied with water, but as we advanced into the lower ground the channel was dry, though increased to twenty yards wide and ten to fifteen feet deep; at 11.15 a.m. one of the horses, Prince, was observed to be unwell, and at 1.20 p.m. a second horse, Bob, was noticed to be suffering from illness, having bled them, we proceeded down the creek in search of water at which the party could halt, and found a small waterhole at 2.20 p.m., but the two sick horses dropped dead about 150 yards before reaching it; their loads had been previously removed to the saddle-horses; as soon as the camp had been formed Mr. Elsey and Dr. Mueller examined the dead horses to ascertain the cause of death, and it appeared from the state of extreme inflammation of the stomachs that they had eaten some poisonous plant; but the food was too much comminuted to admit of the plants eaten being recognised. Latitude by a Coronae Borealis 15 degrees 12 minutes 46 seconds. 22nd July. At 7.10 a.m. resumed our journey down the valley of the creek to the east and east-north-east, passing a fine lagoon with nelumbium and a number of pelicans; at 8.30 a.m. crossed two large creeks and passed a second lagoon, 70 yards by 300 yards. The principal creek now turned to the north, and our course was along the foot of a sandstone range 200 feet high, till 12.40 p.m., when, altering the course to south-east, we ascended the range and crossed the level sandy tableland covered with scrub; descending to the south, found a small dry watercourse in an open valley, and followed it in search of water to the north-west till 4.0 p.m., when we found a small pool of rainwater, at which we camped. Latitude by a Trianguli Australis 15 degrees 13 minutes 6 seconds. 23rd July.