The governor, General Darling, whose multifarious duties might well have excused him from paying attention to distant objects, hesitated not a moment when he thought the interests of the colony, whose welfare he so zealously promoted, appeared to be concerned; and he determined to avail himself of the services of Captain Collet Barker, of the 39th regiment, who was about to be recalled from King George's Sound, in order to satisfy himself as to the correctness of my views. Captain Barker had not long before been removed from Port Raffles, on the northern coast, where he had had much intercourse with the natives, and had frequently trusted himself wholly in their hands. It was not, however, merely on account of his conciliating manners, and knowledge of the temper and habits of the natives, that he was particularly fitted for the duty upon which it was the governor's pleasure to employ him. He was, in addition, a man of great energy of character, and of much and various information. Orders having reached Sydney, directing the establishment belonging to New South Wales to be withdrawn, prior to the occupation of King George's Sound by the government of Western Australia, the ISABELLA schooner was sent to receive the troops and prisoners on board; and Captain Barker was directed, as soon as he should have handed over the settlement to Captain Stirling, to proceed to Cape Jervis, from which point it was thought he could best carry on a survey not only of the coast but also of the interior. This excellent and zealous officer sailed from King George's Sound, on the 10th of April, 1831, and arrived off Cape Jervis on the 13th. He was attended by Doctor Davies, one of the assistant surgeons of his regiment, and by Mr. Kent, of the Commissariat. It is to the latter gentleman that the public are indebted for the greater part of the following details; he having attended Captain Barker closely during the whole of this short but disastrous excursion, and made notes as copious as they are interesting. At the time the ISABELLA arrived off Cape Jervis, the weather was clear and favourable. Captain Barker consequently stood into St. Vincent's Gulf, keeping, as near as practicable, to the eastern shore, in soundings that varied from six to ten fathoms, upon sand and mud. His immediate object was to ascertain if there was any communication with the lake Alexandrina from the gulf. He ascended to lat. 34 degrees 40 minutes where he fully satisfied himself that no channel did exist between them. He found, however, that the ranges behind Cape Jervis terminated abruptly at Mount Lofty, in lat. 34 degrees 56 minutes, and, that a flat and wooded country succeeded to the N. and N.E. The shore of the gulf tended more to the N.N.W., and mud flats and mangrove swamps prevailed along it. INVITING COUNTRY--MOUNT LOFTY.