A little before high water we again embarked. A seal had been observed playing about, and we augured well from such an omen. The blacks had been watching us from the opposite shore, and as soon as we moved, rose to keep abreast of us. With all our efforts we could not avoid the shoals. We walked up to our knees in mud and water, to find the least variation in the depth of the water so as to facilitate our exertions, but it was to no purpose. We were ultimately obliged to drag the boat over the flats; there were some of them a quarter of a mile in breadth, knee-deep in mud; but at length got her into deep water again. The turn of the channel was now before us, and we had a good run for about four or five miles. We had completed the bend, and the channel now stretched to the E.S.E. At about nine miles from us there was a bright sand-hill visible, near which the channel seemed to turn again to the south; and I doubted not that it terminated there. It was to no purpose, however, that we tried to gain it. Shoals again closed in upon us on every side. We dragged the boat over several, and at last got amongst quicksands. I, therefore, directed our efforts to hauling the boat over to the south side of the channel, as that on which we could most satisfactorily ascertain our position. After great labour we succeeded, and, as evening had closed in, lost no time in pitching the tents. BEACH OF ENCOUNTER BAY. While the men were thus employed, I took Fraser with me, and, accompanied by M'Leay, crossed the sand-hummocks behind us, and descended to the sea-shore. I found that we had struck the south coast deep in the bight of Encounter Bay. We had no time for examination, but returned immediately to the camp, as I intended to give the men an opportunity to go to the beach. They accordingly went and bathed, and returned not only highly delighted at this little act of good nature on my part, but loaded with cockles, a bed of which they had managed to find among the sand. Clayton had tied one end of his shirt up, and brought a bag full, and amused himself with boiling cockles all night long. If I had previously any hopes of being enabled ultimately to push the boat over the flats that were before us, a view of the channel at low water, convinced me of the impracticability of any further attempt. The water was so low that every shoal was exposed, and many stretched directly from one side of the channel to the other; and, but for the treacherous nature of the sand-banks, it would not have been difficult to have walked over dry footed to the opposite side of it. The channel stretched away to the E.S.E., to a distance of seven or eight miles, when it appeared to turn south under a small sand-hill, upon which the rays of the sun fell, as it was sinking behind us. CURIOUS EFFECT OF REFRACTION.