Along this new-found watercourse, they were enabled to make easy stages for five days, when the course of the creek was lost; nor could any continuation be traced. The lagoons, too, that were found a short distance from the banks, proved to be intensely salt. Repeated efforts to continue his journey to other points of the compass only led Sturt amongst the terrible sandhills, their parallel rows separated by barren plains encrusted with salt. Sturt now came to the erroneous conclusion that he had reached the head of Eyre's Creek, and that further progress was effectually barred by a waterless tract of country. In fact, he was then within reach of a well-watered river, along which he could have travelled right up to the main dividing range of the northern coast. But Sturt was baffled in the most depressed area on the surface of the continent, where rivers and creeks lost their identity in the numberless channels into which they divided before reaching their final home in the thirsty shallows of the then unknown Lake Eyre. There was neither sign nor clue afforded him; his men were sick, and any further progress would jeopardise his retreat. There was nothing for it but to fall back once more; and, after a toilsome journey, they reached Fort Grey on the 2nd of October.
Sturt's last effort had been made to the west of north; he now made up his mind for a final effort due north. Before starting, however, he begged of Browne, who was still suffering, to retreat, while the way was yet open, to the Darling. This Browne resolutely refused to do; stating that it was his intention to share the fate of the expedition. The 9th of October saw Sturt again under way to the seemingly forbidden north, Stuart and two fresh men accompanying him. On the second day they reached Strzelecki Creek, and on the 13th they came on to the bank of a magnificent channel, with fine trees growing on its grassy banks, and abundance of water in the bed. This was the now well-known Cooper's Creek, which Sturt, on his late trip, had crossed unnoticed, as it was then dry and divided into several channels on their route. This was the most important discovery made in connection with the lake system, Cooper's Creek being one of the far-reaching affluents, its tributaries draining the inland slopes of the main dividing range.
Sturt, on making this unexpected discovery, was undecided whether to follow Cooper's Creek up to the eastward or persevere in his original intention of pushing to the north. A thunder-storm falling at the time made him adhere to his original determination, and defer the examination of the new river until his return.
Seven days after crossing Cooper's Creek, he had the negative satisfaction of seeing his gloomy forebodings fulfilled. Once more he gazed over the dreary waste of the stony desert, unchanged and repellant as ever. They crossed it, but were again turned back by sandhill and salt plain, and forced to retrace their steps to Cooper's Creek. This creek Sturt followed up for many days, but found that it came from a more easterly direction than the route he desired to travel along; moreover, the one broad channel that they had commenced to follow became divided into several ana-branches, running through plains subject to inundation. This became so tiring to their now exhausted horses, who were woefully footsore, that he reluctantly turned back. He had found the creek peopled with well-nurtured natives, and the prospects of advancing were brighter than they had ever been; but both Sturt and his men were weak and ill, and the horses almost incapable of further effort. Moreover, he was not certain of his retreat.
As they went down Cooper's Creek on their way back, they found that the water was drying up so rapidly that grave fears were entertained lest Strzelecki's Creek, their main resource in getting back to Fort Grey, should be dry. Fortunately they were in time to find a little muddy fluid left, just enough to serve their needs. Here, though most anxious to get on, they were forced to camp the whole of one day, on account of an extremely fierce hot wind.
Sturt's vivid account of the day spent during the blast of that furnace-like sirocco has been oft quoted. But the reader should remember when reading it that the man who wrote it was in such a weakened condition that he had not sufficient energy left to withstand the hot wind, whilst the shade under which the party sought shelter was of the scantiest description.
They had still a distance of eighty-six miles to cover to get back to Fort Grey, with but little prospect of finding water on the way. After a long and weary ride they reached it, only to find the tents struck, the flag hauled down, and the Fort abandoned. The bad state of the water and the steady diminution of supply had forced Browne to fall back to Depot Glen, riding day and night Sturt reached the old encampment, so exhausted that he could hardly stand after dismounting.
The problem of their final escape had now to be resolved. The water in Depot Creek was reduced so low that they feared there would be none left in Flood's Creek. If this failed, they were once more imprisoned. Browne, now much recovered, undertook the long ride of one hundred and eighteen miles which would decide the question. Preparations had been made for his journey by filling a bullock skin with water, and sending a dray with it as far as possible. On the eighth day he returned.
"Well, Browne," asked Sturt, who was helpless in his tent, "what news? Is it good or bad?" "There is still water in the creek," replied Browne, "but that is all I can say; what there is is as black as ink, and we must make haste, for in a week it will be gone."
The boat that was to have floated over the inland sea was left to rot at Depot Glen. All the heaviest of the stores were abandoned, and the retreat of over two hundred miles commenced.