The good fortune which had followed Sir Thomas Mitchell throughout his three earlier expeditions did not forsake him during this one, which proved to be the last and most arduous of the series. It was his ambition this time to cross the continent and open an overland route to the distant Carpentaria. Of all men living, he was the most likely to accomplish this task. He did not, indeed, attain the desire of his heart, but in all other respects his expedition was eminently successful, and forms a memorable epoch in the history of exploration. The party mustered at the old rendezvous of Buree, in the Western District, which, though no longer the outpost of settlement, was yet a convenient starting-point. Mitchell chose for his second in command Mr. Edmund B. Kennedy, the unfortunate explorer who, several years later, was killed by the blacks when leading a disastrous expedition in Cape York Peninsula. The rest of the party were mostly convicts from Port Jackson, who had volunteered their services in the hope of obtaining their freedom. The little army, consisting of two dozen able-bodied men, amply provisioned, left Buree on the 15th of December, 1845. The old route was followed for a considerable way, and in a short time the Hervey Range, containing the sources of the Bogan, was crossed without serious difficulty. For a long distance westward the country was now occupied by squatters, but many of the outsiders had already succumbed to the hostility of the Darling blacks, who had speared their cattle and otherwise harassed them beyond the limit of human endurance. Ten years had now passed away since Mitchell led his preceding expedition through these parts, and the abortive attempts at settlement were the principal changes observable in the general aspect of the country. One very remarkable minor feature was the appearance of couch-grass and horehound, which had sprung up around the stockyards. Mitchell was quite positive in asserting that no specimen of these plants could have been found in the district before the white men settled there. The party suffered from want of water till Nyngan was reached, on the 16th January, and then one difficulty was quickly followed by another. Most of the men were seized with eye-blight, and compelled to remain in camp longer than was convenient for the object of the expedition. But they were again on the move as soon as circumstances would permit, the march being now directed towards the Macquarie. Meanwhile an encampment was made on the Canonbar, a tributary of the Bogan. While resting here the saltbush became an object of curiosity, and some interesting experiments were made with this singular plant of the interior plains. The tiny leaves were found to be a tolerable substitute for vegetables after boiling, by which process a yield of pure salt was obtained in the proportion of one ounce to the pound. The condition of the stock also bore witness to the fattening quality of the same plant.