When the long-expected rain fell, they pushed on for fifty miles to another suitable halting-place, which was called Park Depot. From this depot Captain Sturt made two attempts to reach the Centre of the continent. He started, accompanied by four of his party, advancing over a country which resembled an ocean whose mighty billows, fifty or sixty feet high, had become suddenly hardened into long parallel ridges of solid sand. The abrupt termination of this was succeeded at two hundred miles by what is now so well known as Sturt's Stony Desert, to which frequent allusion is made by Mr. Stuart in his journals. After thirty miles more, this stony desert ceased with equal abruptness, and was followed by a vast plain of dried mud, which Captain Sturt describes as "a boundless ploughed field, on which floods had settled and subsided." After advancing two hundred miles beyond the Stony Desert, and to within one hundred and fifty miles of the Centre of the continent, they were compelled to return to Park Depot, where they arrived in a most exhausted condition. A short rest at the Depot was followed by another expedition, Captain Sturt being on this occasion accompanied by Mr. Stuart and two men. The seventh day of their journey brought them to the banks of a fine creek, now so well known as Cooper Creek in connection with the fate of those unfortunate explorers, Burke and Wills. At two hundred miles from Cooper Creek Captain Sturt and his party were again met by the Stony Desert, but slightly varied in its aspect. Before abandoning his attempt to proceed, the leader of the expedition laid the matter before his companions, and he writes as follows: "I should be doing an injustice to Mr. Stuart and my men, if I did not here mention that I told them the position we were placed in, and the chance on which our safety would depend if we went on. They might well have been excused if they expressed an opinion contrary to such a course; but the only reply they made me was to assure me that they were ready and willing to follow me to the last." With much reluctance, however, Captain Sturt determined to return to Cooper Creek without delay. They travelled night and day without interruption, and on the morning of their arrival at the creek, one of those terrible hot north winds, so much dreaded by the colonists, began to blow with unusual violence. Lucky was it for them that it had not overtaken them in the Desert, for they could scarcely have survived it. The heat was awful; a thermometer, graduated to 127 degrees, burst, though sheltered in the fork of a large tree, and their skin was blistered by a torrent of fine sand, which was driven along by the fury of the hurricane. They still had fearful difficulties to encounter, but after an absence of nineteen months they returned safely to Adelaide.