In passing out, we named two low small rocky islands, lying north of Point Swan, and hitherto unhonoured with any particular denomination, the Twins. It should be noted, that the tide did not begin to make to the southward till 8 hours 15 minutes A.M., being full half an hour after low-water by the shore. We passed through several tide races; not, however, feeling their full force, owing to our encountering them at the time of slack water. In every case our soundings indicated great irregularity of bottom, the cause to which I have already assigned these impediments to in-shore navigation. SUNDAY STRAIT. We found a temporary anchorage the same morning, on the east side of the large group forming the eastern side of Sunday Strait; so named by Captain King, who was drifted in and out of it on that day, August 19th, 1821, amid an accumulation of perils that will long render the first navigation of this dangerous Archipelago a memorable event in the annals of nautical hardihood. ROE'S GROUP. This group we called after Lieutenant Roe, R.N., Surveyor-General of Western Australia, who had accompanied Captain King in that perilous voyage, and whose valuable information had enabled us to escape so many of the dangers to which our predecessors had been exposed. Nothing could exceed the desolate appearance of the land near which we were now lying: rocks, of a primitive character, massed together in all the variety of an irregularity, that rather reminded the beholder of Nature's ruin than her grandeur, rose, drear and desolate, above the surrounding waters; no trees shaded their riven sides, but the water-loving mangrove clothed the base of this sterile island, and a coarse, wiry grass was thinly spread over its sides. MIAGO AND HIS FRIENDS. Soon after we had anchored, some natives were observed by Miago watching us from the shore; and shortly afterwards a party landed, to attempt communicating with them, and to get the necessary observations for the survey. In the first object they failed altogether; for these blackfellows, as that gallant hero called them, retired to the heights, and, while closely watching every movement, refused to trust themselves within our reach. The smallness of their number, and their want of arms, quite elevated the courage of Miago, who loudly vaunted his intention of monopolizing a northern gin, in order to astonish his friends upon our return to the south: stealing away the ladies being, as I have before remarked, the crowning and most honourable achievement of which man, in the eyes of these savages, is capable. I ought not to omit remarking here, that the natives seen to-day were accompanied by a black dog; the only instance in which, before or since, we observed the existence of a dog of that colour in this vast country. Captain King mentions that he saw one in this neighbourhood during his visit in 1821. DAY OF REST.