We left Hobart Town for Sydney on July 8th.  On the night of the 15th, saw the fine revolving light on the South Head of Port Jackson, and next morning anchored at Farm Cove.  Our stay in Sydney was protracted to a period of nearly three months.  During this time, in consequence of previous arrangements, the schooners Bramble, Lieutenant C.B.  Yule, and Castlereagh, Lieutenant D. Aird, were paid off.  Both these vessels had been left in December, 1845, by Captain F.P.  Blackwood, of H.M.S.  Fly, to continue the survey of New Guinea (as will afterwards be more particularly alluded to) and had long been awaiting our arrival.  The Castlereagh, originally purchased in Sydney, being reported to be quite unfit for surveying purposes, was sold to her former owner; and the Bramble was recommissioned as tender to the Rattlesnake, and continued under the command of Lieutenant Yule.  Ten additional men were entered on board, increasing our complement to 190 officers and men, of whom 36 were placed on board the schooner.  After a thorough refit, both vessels were at length quite ready for sea.

Survey entrance of port Jackson.

Meanwhile a minute survey was made by Lieutenants Dayman and Simpson of the inner entrance to Port Jackson, where a reef, called the Sow and Pigs (distinguished by a beacon and a light vessel) in the middle of the passage, leaves only a narrow available channel on either side.  The exact boundaries of them, with the depth of water, were to be determined, especially to ascertain whether a line-of-battle ship, with her full armament, could pass into the harbour.  The shoalest part of the west channel was found to have 21 feet, and of the east 24 feet at low-water (the rise and fall of tide being from 5 to 8 feet); consequently, at high-water there would be room for a three-decker to enter.* This work was in connection with a proposed dry dock** on Cockatoo Island, above Sydney, towards the expenses of which the Imperial Government were willing to contribute, provided it were made of such a size as to be available for large steamers and line-of-battle ships.

(Footnote.  It was found by comparison with Lieutenant Roe’s survey, made 25 years before, that the inner edge of the shoal had extended considerably to the southward.)

(**Footnote.  This has for several years been under construction; its importance will appear more evident, when it is considered that a large vessel in the Australian colonies requiring repairs, which cannot be effected by the process of heaving down, will find no suitable place nearer than Bombay.)

In compliance with a requisition from Sir Charles Fitzroy, the Governor of New South Wales, Captain Stanley, in the Bramble, paid a visit to Twofold Bay, 200 miles to the southward of Sydney, a place of rising importance as a harbour, also in connection with whaling establishments, and the extensive adjoining pastoral district of Maneroo.  The bay was resurveyed, with a view to test the comparative merits of the two townships there—­one founded by government, the other by private enterprise.  After all, I believe, the advantages afforded by each of the rival establishments are so equally divided, that the question still remains an open one.