So for two or three days they continued on the Oakover, as he christened the river, and followed its western branch; a tributary of that led them in amongst the ranges, which were threaded by an easy pass. On the 2nd of September they got through the ranges and emerged upon open sandy plains of great extent, with nothing visible across the vast expanse but low ridges of red drift-sand. Here it was Gregory's lot to experience a test almost equal to one of the grim tramps that had tried Sturt and Eyre.
He camped at a native deserted camp, and the next day failing to find any water ahead, had to return and form a depot. Here he left five of the party with instructions to remain three days and then fall back upon the Oakover. He himself, with Brown and Harding, and six horses, went on to find a passage.
So far he had encountered fewer obstacles, and made more encouraging discoveries than had fallen to the lot of any other Western Australian explorer; but he was now confronted with the stern presence that had daunted the bravest and best in Australia. In front of him lay barren plains, hills of drifted sand, and the ominous red haze of the desert. Let Gregory describe the scene in his own words, as the locality has become historic:--
The three men started on the 6th of September, "steering south-south-east along the ranges, looking for some stream-bed that might lead us through the plains, but I was disappointed to find that they were all lost in the first mile after leaving the hills, and as crossing the numerous ridges of sand proved very fatiguing to the horses, we determined once more to attempt to strike to the eastward between the ridges, which we did for fifteen miles, when our horses again showed signs of failing us, which left us the only alternative of either pushing on at all hazards to a distant range that was just visible to the eastward, where, from the numerous native fires and general depression of the country, there was every reason to think a large river would be found to exist, or to make for some deep rocky gorges in the granite hills ten miles to the south, in which there was every prospect of finding water. In the former case the travelling would be smoothest, but the distance so great that, in the event of our failing to find water, we probably should not succeed in bringing back one of our horses; while in the latter we should have to climb over the sand-ridges which we had already found so fatiguing; this course, however, involved the least amount of risk, and we accordingly struck south four miles and halted for the night.
"7th September. The horses did not look much refreshed by the night's rest; we, however, divided three gallons of water amongst them, and started off early, in the hope of reaching the ranges by noon, but we had not gone three miles when one of the pack-horses that was carrying less than forty pounds weight began to fail, and the load was placed on my saddle-horse; it did not, however, enable him to get on more than a couple of miles further, when we were compelled to abandon him, leaving him under the shade of the only tree we could find, in the hope that we could bring back water to his relief. Finding that it would be many hours before the horses could be got on to the ranges, I started ahead on foot, leaving Brown and Harding to come on gently, while I was to make a signal by fires if successful in finding water. Two hours' heavy toil through the sand, under a broiling sun, brought me to the ranges, where I continued to hunt up one ravine after another until 5 p.m. without success. Twelve hours' almost incessant walking, on a scanty breakfast and without water, with the thermometer over a hundred degrees of Fahrenheit, began to tell upon me severely; so much so that by the time I had tracked up my companions (who had reached the hills by 1 p.m. and were anxiously waiting for me) it was as much as I could do to carry my rifle and accoutrements. The horses were looking truly wretched, and I was convinced that the only chance of saving them, if water was not found, would be by abandoning our pack-saddles, provisions, and everything we could possibly spare, and try and recover them afterwards if practicable. We therefore encamped for the night on the last plot of grass we could find, and proceeded to make arrangements for an early start in the morning. There was still a few pints of water in the kegs, having been very sparing in the use of it; this enabled us to have a little tea and make a small quantity of damper, of which we all stood in much need. Camp 77.
"8th September. At 4 p.m. we were again up, having disposed of our equipments and provisions, except our riding-saddles, instruments, and firearms, by suspending them in the branches of a low tree. We divided a pint of water for our breakfast, and by the first peep of dawn were driving our famished horses at their best speed towards the depot, which was now thirty-two miles distant. For the first eight miles they went on pretty well, but the moment the sun began to have power they flagged greatly, and it was not long before we were obliged to relinquish another horse quite unable to proceed. By 9 a.m. I found that my previous day's march, and the small allowance of food that I had taken was beginning to have its effects upon me, and that it was probable that I could not reach the depot before the next morning, by which time the party left there were to fall back to the Oakover; I therefore directed Brown, who was somewhat fresher than myself, to push on to the camp and bring out fresh horses and water, while Harding and myself would do our best to bring on any straggling horses that could not keep up with him. By dark we succeeded in reaching to within nine miles of the depot, finding unmistakable signs towards evening of the condition to which the horses taken on by Brown were reduced, by the saddles, guns, hobbles, and even bridles, scattered along the line of march, which had been taken off to enable them to get on a few miles further."
Next morning they met Brown within a few miles of the depot coming back to them with water. All the horses but the two which had been left at the remotest point were recovered.
Further on Gregory remarks upon the painful effects produced on the horses by excessive heat and thirst:--
"I cannot omit to remark the singular effects of excessive thirst upon the eyes of the horses; they absolutely sunk into their heads until there was a hollow of sufficient depth to bury the thumb in, and there was an appearance as though the whole of the head had shrunk with them, producing a very unpleasant and ghastly expression."
Gregory was now convinced that the sandy tract before him was not to be crossed with the means at his command, so reluctantly he had to return to the Oakover and follow that river down to its junction with the De Grey. Down the united streams, which now bore the name of the De Grey, the weary explorers travelled through good fertile land, until the coast was reached on the 25th of September. The worn-out state of their horses delayed them greatly in getting across a piece of dry country between the Yule and the Sherlock, where one animal had to be abandoned.