Having finished my reports and letters, it became necessary to consider the best point on which to move, and to fix a day for our departure from Mount Harris. It struck me that having found so important a feature as the Darling River, the Governor would approve my endeavouring to regain it more to the southward, in order to trace it down. I, therefore, detached Mr. Hume to survey the country in that direction, and to ascertain if a descent upon the Bogen district would be practicable, through which I had been informed a considerable river forced itself. The report he made on his return was such as to deter me from that attempt, but he stated that the country for 30 miles from the Macquarie was well watered, and superior to any he had passed over during the journey; beyond that distance, it took up the character of the remote interior, and alternated with plains and brush, the soil being too sandy to retain water on its surface. He saw some hills from the extremity of his journey, bearing by compass W.S.W. We consequently determined to make for the Castlereagh, agreeably to our instructions. Preparations were made for breaking up the camp, all the various arrangements in the change of animals were completed, the boat carriage was exchanged for a dray, and I took Boyle in the place of Norman, whose timidity in the bush rendered him unfit for service. CIRCUIT OF THE GREAT MARSHES. There is a small hill on the opposite side of the river, and immediately facing Mount Harris, and to the S.E. of it there is a small lagoon, the head of a creek, by means of which its superfluous waters are carried off. This creek runs parallel to the river for about ten miles, and enters the marshes at the S.E. angle. This I ascertained one day in riding to carry on my survey of the southern extremity of the marshes, and to join my line of route by making the circuit of that part of them. I found that the river was turned to its northerly course by a rising ground of forest land, which checks its further progress westerly. I proceeded round the S.W. angle, and then, taking a northerly course, got down to the bottom of the first great marsh, thus completing the circuit of them. I did not return to the camp until after 10 p.m., having crossed the river at day-light, nor did we procure any water from the time we left the stream to the moment of our recrossing it. WALLIS'S PONDS.