at 100 degrees in the shade when we rested under the quandongs.  In the night blankets were unendurable.  Had there been any food for them the horses could not eat for thirst, and were too much fatigued by yesterday’s toil to go out of sight of our camping place.  We followed along the course of the lake north of west for seven miles, when we were checked by a salt arm running north-eastwards; this we could not cross until we had gone up it a distance of three miles.  Then we made for some low ridges lying west-south-west and reached them in twelve miles.  There was neither watercourse, channel, nor rock-holes; we wandered for several miles round the ridges, looking for water, but without success, and got back on our morning’s tracks when we had travelled thirty miles.  From the top of these ridges the lake could be seen stretching away to the west or west-south-west in vast proportions, having several salt arms running back from it at various distances.  Very far to the west was another ridge, but it was too distant for me to reach now, as to-night the horses would have been two nights without water, and the probability was they would get none there if they reached it.  I determined to visit it, however, but I felt I must first return to the tank in the little glen to refresh the exhausted horses.  From where we are, the prospect is wild and weird, with the white bed of the great lake sweeping nearly the whole southern horizon.  The country near the lake consists of open sandhills, thickly bushed and covered with triodia; farther back grew casuarinas and mulga scrubs.

It was long past the middle of the day when I descended from the hill.  We had no alternative but to return to the only spot where we knew water was to be had; this was now distant twenty-one miles to the north-east, so we departed in a straight line for it.  I was heartily annoyed at being baffled in my attempt to reach the mountain, which I now thought more than ever would offer a route out of this terrible region; but it seemed impossible to escape from it.  I named this eminence Mount Olga, and the great salt feature which obstructed me Lake Amadeus, in honour of two enlightened royal patrons of science.  The horses were now exceedingly weak; the bogging of yesterday had taken a great deal of strength out of them, and the heat of the last two days had contributed to weaken them (the thermometer to-day went up to 101 degrees in shade).  They could now only travel slowly, so that it was late at night when we reached the little tank.  Fifty miles over such disheartening country to-day has been almost too much for the poor animals.  In the tank there was only sufficient water for one horse; the others had to be tied up and wait their turns to drink, and the water percolated so slowly through the sand it was nearly midnight before they were all satisfied and begun to feed.  What wonderful creatures horses are!  They can work for two and three days and go three nights without