Exploring through a fog. Lakes. Circular Lake of Boga. Clear grassy hills. Natives on the lake. Scarcity of fuel on the bank of a deep river. Different character of two rivers. Unfortunate result of Piper's interview with the natives of the lake. Discovery of the Jerboa in Australia. Different habits of the savage and civilized. A range visible in the south. Peculiarities in the surface of the country near the river. Water of the lakes brackish, or salt. Natives fly at our approach. Arrival in the dark, on the bank of a watercourse. Dead saplings of ten years growth in the ponds. Discovery of Mount Hope. Enter a much better country. Limestone. Curious character of an original surface. Native weirs for fish. Their nets for catching ducks. Remarkable character of the lakes. Mr. Stapylton's excursion in search of the main stream. My ride to Mount Hope. White Anguillaria. View from Mount Hope. Return of Mr. Stapylton. SWAN HILL. June 21. Among the reeds on the point of ground between the two rivers was a shallow lagoon where swans and other wild fowl so abounded that, although half a mile from our camp, their noise disturbed us through the night. I therefore named this somewhat remarkable and isolated feature Swan Hill, a point which may probably be found to mark the junction of two fine streams. EXPLORING THROUGH A FOG. I wished to devote the day to meteorological observations as prearranged with my friends in the Colony, Mr. Dunlop and Captain King; but a thick fog in the morning promised a day of clear settled weather, and I was obliged to proceed; I observed the barometer however every hour during the journey. For several miles we travelled through the mist over plains partly covered with reeds and partly with grass. Having reconnoitred the country on the previous evening I had no difficulty in pursuing the direction I then chose for this day's route. LAKES. CIRCULAR LAKE OF BOGA. At eleven A.M. when the fog arose I perceived a low grassy ridge before us; and a fine lake covered with black swans, ducks and other waterfowl was afterwards discovered beyond it. We passed along the southern shore of this lake, thus keeping it between us and the river. It was surrounded with reeds and bulrushes, and appeared to be supplied by a small feeder from the river, like other similar lakes which we had seen near rivers elsewhere: but the water could pass by such small channels only during the highest floods, for the lake was even then very low, although the flood in the river was evidently high. This lake was about three miles in circumference. CLEAR GRASSY HILLS.