As we were rounding Breaksea Spit, we met four merchant ships, who gladly availed themselves of our convoy. On the 6th, being anxious to repeat our last meridian distance, and also the magnetic observations, we anchored under Cape Upstart. We likewise availed ourselves of the visit to complete the examination of the bay on the east side of the Cape. The 7th was a remarkably gloomy day, signalized by a very unusual fall in the barometer between 8 A.M., and 2 P.M., from 30.14 to 30.00, when the breeze which had been fresh in the morning, increased to a gale with squalls. At 3, the wind shifted to the southward, and at 8 when it moderated, the barometer again rose to 30.17. It is these sudden breezes that are so fatal to ships caught off the outer barrier without an opening to get within its shelter. No traces of natives were seen; but the supply of water was as abundant as before, and we took the opportunity of completing our stock. MAGNETICAL ISLAND. On the 8th in the evening we left for Magnetical Island, about half a mile off the west side of which we anchored next day in 5 fathoms. The depth from thence shoals in gradually to the head of the bay. A small rocky islet, to which our observations refer, bore south half a mile, in latitude 19 degrees 7 minutes 10 seconds South and longitude 4 degrees 29 minutes 12 seconds West of Sydney. On this I found a greyish kind of slate; but on Magnetical Island I discovered no local attraction affecting the needle, so as to warrant the name bestowed by Cook. It is a high piece of land, with an ill-defined peak in the centre, 1770 feet high. A description and view of it have been given in the first volume. We remained there five days, in order to rate the chronometers, and to examine the head of Halifax Bay, where a large estuary had been reported by Captain King; but of this we could see nothing, and came to the conclusion that he must have been deceived by mirage. The land certainly was low in that direction, and trending in to the southward appeared afterwards to wind round to South-West, offering facilities for getting over the range before spoken of as 3,600 feet high, and bounding the shore of Halifax Bay. We were, however, glad of this opportunity of examining a portion of the continent, that had always excited the attention of those who passed, by its fertile aspect. HALIFAX BAY.