obart 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