four miles and a half east from the south-east point of Clarke Island; there is, however, a narrow passage of 16 fathoms close to the latter.  This Bank, which has a couple of rocks near its north-eastern part, is steep to, and may be avoided by keeping the south point of Clarke Island, to bear to the southward of West 12 degrees North.  Mount William, also, bearing South 7 degrees West clears the outer end of it.

(Footnote.  This reef is a low, dark, rocky islet, with reefs extending off North 45 degrees West three quarters of a mile, and South 56 degrees East, one mile.  There is a passage of 7 fathoms, a mile wide, between it and the main, through which the highest St. George’s Rock, bearing South 52 degrees East, leads.  Black Reef bears from the latter North 45 degrees West, six miles and a half, and from the summit of Swan Island, South 53 degrees East, eight miles and three-quarters.  Mount William, also, bears from it South 22 degrees West.)

I may here mention, that the importance of Banks Strait is great, as all the trade between Hobart, Launceston, and Port Phillip, passes through it.

SWAN ISLAND.

Swan Island is a narrow hummocky strip of land, a mile and a half long, trending South-West by West; the loftiest part, 90 feet high, near the north end,* was selected by Sir John Franklin for the site of a lighthouse, the foundation of which he laid, after resigning the reins of government; it was the last benefit he was able to confer on the colony.

(Footnote.  In latitude 40 degrees 43 minutes 36 seconds South, longitude 3 degrees 5 minutes 50 seconds West of Sydney, and 148 degrees 10 minutes 10 seconds East of Greenwich; variation, 10 east.)

A well of indifferent water was found near the north-west end of the island; and some sealers had recently turned loose a couple of pigs, to which I added a third.

Two small islets lie one mile and a half West-North-West from Swan Island, and a dangerous patch of rocks, one and a quarter North-West by West from the summit; they are all connected with the large island by shoal water.

TIDES.

We found the best anchorage to be a quarter of a mile off the south point of a sandy bay, near the outer end of the island.  During the time we lay here for the purpose of obtaining a series of tidal observations,* and verifying a few of the principal points of Messrs. Forsyth and Pasco’s survey, constant strong westerly gales prevailed; and from all the local information obtained it appeared that such was generally the case.

(Footnote.  The result of these observations makes the time of high-water at the full and change of the moon 9 hours 36 minutes when the rise of the tide is six feet and three at neaps.  The flood-stream comes from the eastward; and both it and the ebb is of 6 hours 15 minutes duration at springs; but during neaps the flood runs 7 hours 0 minutes and the ebb 5 hours 30 minutes.  The interval of slack-water