It was now necessary to resume our examination of the Abrolhos, and thirty-one miles on a West 1/4 South course, brought us between two groups of them, where we anchored for the night in 23 fathoms. The soundings in standing across Geelvink Channel, were 22 and 26 fathoms, fine white sand; the current ran North-North-West, a mile an hour. April 11. At daylight we found that the summit of a large island, in the centre of the group to the northward, bore North 21 1/2 degrees West about nine miles. GOOD FRIDAY HARBOUR. We now beat to the southward in search of a harbour, where the ship might lie in safety whilst we went to work with the boats, and were fortunate enough to discover one close to the north-east point of a large island lying in the centre of the group to the southward; which we named Easter Group, and the harbour Good Friday Harbour, to commemorate the season of the Christian year, at which we visited it. Perhaps at some future period, when the light of the gospel shall have penetrated to every part of the vast Australian continent, these sacred names, bestowed by us upon some of its outworks, may be pronounced with pleasure, as commemorative of the time when the darkness of ignorance and superstition was just beginning to disperse. Good Friday Harbour, like all coral harbours, requires to be taken by eye, being full of coral knolls, which necessitate the utmost vigilance. In itself, however, it is an excellent port, capable of holding a large number of ships, and with a general depth, between the coral patches, of from 15 to 17 fathoms, with a fine muddy sandy bottom. The eastern extremity of the large island bearing South by East 1/2 East led into the harbour. As we threaded our way among the patches of coral, the view from the masthead of the submarine forests through the still pellucid water was very striking. The dark blue of the deep portions of the lagoon contrasted beautifully with the various patches of light colours interspersed. We found to our surprise that the group into which we had penetrated was entirely distinct from that under which we had first anchored to the southward, so that we had already discovered the Abrolhos to form three separate groups. RAT ISLAND.