In the evening the anchor was dropped about a mile from the north side of the Bird Isles in ten fathoms, a sudden degree from fifteen, just before standing in West-South-West to the anchorage. Five miles South-East by East from these isles, we passed close to the position of a patch of shoal water, according to the chart: its presence, however, was not detected, the depth at the time being nineteen fathoms. The only additions made to the chart during the day were a few soundings, besides increasing the number and altering the position of Cockburn Islands, with the reefs fronting them. The number of these isles is thus increased from two to four; they are square rocky lumps, the largest being three hundred feet high. The current during the day set steadily North-West almost a mile an hour. On anchoring we found it setting West-North-West at the same rate. At midnight it changed its direction to East-South-East from a quarter to half a knot an hour. The time of high-water being about 6 A.M., it is evident the flood-stream came here from South or South-East. The islands passed during the day, were of a small lagoon character and the reefs oval-shaped, with an elevated patch of dead coral at their north extreme, which had the appearance, at a distance, of sand. The mainland had much changed in outline, having subsided into a wearisome series of undulating hills, varying from five to seven hundred feet in height. The coast was, therefore, utterly void of any feature of interest, after passing Fair Cape. July 11. At daylight we were again underway and steered North by East for the purpose of ascertaining if there were any reefs to the eastward of u and v. When Number 1 of a group next south of Cairncross bore North 43 degrees West four and a half miles the course was changed to West-North-West to pass between the reef fronting its south side and reef w where we had a depth of 20 fathoms; both of these we found it necessary to enlarge on the chart. At the time of altering the course, the ship was West-North-West two miles from the position of an island according to chart; but as we did not see it, and as Captain King has not laid it down upon his own authority, we may safely conclude that it either does not exist, or that it is much out of position. BOYDAN ISLAND.