parts, yet there are some straggling rocks off the South point of Watson's Bay, and also round Shark's Island.

There is good anchorage in all parts of the harbour when within the middle head. There is also anchorage in North Harbour, but not to be recommended, for the swell sometimes rolls heavily in there; but no swell can affect the anchorage between Middle Head and the Sow and Pigs.

SYDNEY COVE is nearly half a mile long and 200 fathoms wide, and would contain upwards of twenty ships swinging at their moorings. The shores are bold-to, and, excepting the rocky shoals that extend off Point Bennilong and Point Dawes, ships may approach very near.

The tide rises from 6 to 8 feet, and at full and change it is high water in Sydney Cove at 8" 30', but at the heads it precedes this time by a quarter of an hour. The variation of the compass observed at Sydney Cove, in 1822, was 8° 42′ E.; at Garden Island, 9° 6′; and at Camp Cove, 9° 42'.

If a ship bound to Port Jackson should, from want of observations, be uncertain of her latitude, and fall in with the land either to the southward or northward of it in blowing weather, she may find shelter in Botany Bay or in Broken Bay, as circumstances require. The former is about 3 leagues to the southward, and the latter about 5 leagues to the northward of Port Jackson; and it is of the utmost consequence that such ships as may happen to be in bad condition, and unable to keep off shore, should be aware of these useful places of refuge.

BOTANY BAY is about 9 miles South of the entrance of Port Jackson. The entrance is clear, and lies between Cape Banks and Cape Solander, the latter in lat. 34° 0' 45" S., lon. 151° 15' 50". Steer through mid-channel, and anchor on the North shore.

JERVIS BAY is in lat. 35° 7'. It is formed to the North by Cape Perpendicular, formed of high cliffs, with a flat summit, without tree or shrub, in lat. 35° 6′ 28′′, lon. 151° 2. This entrance is 1 or 2 miles wide.

CAPE GEORGE, in lat. 35° 10', lon. 150° 59', is to the southward of Jervis Bay, and is the best landfall to make on this coast, particularly in thick or hazy weather, when ships are uncertain of their latitude, it being no more than 25 leagues from Port Jackson.

CAPE DROMEDARY is in lat. 36° 18', and has a double mountain over it, which Cook thence called Mount Dromedary. It is high, and may be seen 20 leagues off. Six miles to the eastward is Montague Island, 2 miles long, with anchorage to the West.

TWOFOLD BAY is a place of some interest, as a new town, Boyd, is springing up. On Toraraga Point a landmark, called the Wanderer's Tower, has been erected, which may easily be seen 15 miles off, and points out the position. Point Brierly, according to Capt. Stokes, is in lat. 37° 6' 40", lon. 149° 57′ 42′′, and lies between East and West Boyd.

CAPE HOWE is the S.E. extremity of Australia, and the North side of the entrance to Bass's Strait. It is a low point of rocks and sand, with a small island close to it.

The lighthouse is on Gabo Island, 5 miles to the S.W. of the cape. It is

about 1 miles long, with anchorage on its S. W. side for small vessels, but no channel inside it.

BASS'S STRAIT, as is well known, separates Australia from Van Diemen's Land. On the South side is a group of islands, of which Flinders' or Great Island is the principal. To the N.W. of this is a small cluster, the Kent Group; on the eastern part an excellent and conspicuous lighthouse has been erected (in 1846). The light is 890 feet above the sea; revolves once in fifty-four seconds, and has been seen 37 miles off.

BANKS STRAIT lies to the North of the N.E. point of Van Diemen's Land. On Swan Island, on its South side, is a lighthouse, showing a flashing light, two and a half seconds in every five minutes, visible 30 miles off. It is 104 feet above the sea.

EDDYSTONE POINT is the first marked projection on the East coast of Van Diemen's Land. It is lofty, and in the interval between the Swan Islands are two groups of singular peaked rocks, like villages. St. Helen's Point is 19 miles South of Eddystone Point; the coast here presents several remarkable points of a pyramidal shape in the interior. There is a ledge of rocks above water, reaching a league off the cape. Maurouard Island, to the South of the cape, affords some fresh water.

FREYCINET PENINSULA and SCHOUTEN ISLAND are high, steep, and barren to the eastward, and from these irregularities, at a distance have the appearance of a chain of islands. Fleurieu Bay, to the West of them, affords good anchorage anywhere.

MARIA ISLAND consists of two peninsulas; the bay to the East, named Reidlé Bay, is a bad anchorage to stay in, as it is open entirely to the East and South. The Pyramid, off the South end of the island, is in lat. 42° 45', lon. 148° 3'.

CAPE PILLAR is the most remarkable land on the coast, being a series of perpendicular basaltic columns, rising to a great height, with a flat surface. A high island, Tasman's Island, of similar appearance, lies close to the South of it. It is in lat. 43° 12', lon. 148° 0'.

STORM BAY, the eastern entrance to Hobarton, is between Cape Pillar on the East, and Tasman's Head to the S.W. They are 35 miles apart, N.E. by E. and S.W. by W.

In the N.W. corner of Storm Bay, between Cape Sortie, the North end of Bruny Island, and Cape Direction, lies the mouth of the River Derwent. Seven miles north-eastward from Cape Direction is the mouth of North Bay, leading to Pitt Water and Norfolk Bay. On the western shore is Adventure Bay, the South point of which, named Fluted Cape, is high, steep, and projecting, composed of basaltic columns, and covered with trees; and adjacent to its northern part is Pinguin Island, of moderate height, and also covered with trees. This bay is a good place of shelter from S.W. and westerly gales of wind.

RIVER DERWENT.-The entrance of this river, between Cape Sortie and Cape Direction, is about 2 miles wide, and continues of the same breadth for 5 miles, to the South point of Double Bay, which extends 6 miles North and South, and 2 miles in depth; with an entrance of 13 miles wide, and the soundings from 7 to 2 fathoms.

HOBARTON stands on the West bank of the river, about 10 miles from Cape Sortie; it is situated on a gently sloping plain, at the foot of the Mount Table, and is nearly a mile in length, from North to South. Fort Mulgrave, on the South point of Sullivan Cove (the port of Hobarton), is in lat. 42° 53′ 35′′ S., lon. 147° 21' 30" E.; variation of the compass, 9° 10′ E.

Ships from the westward, bound into the Derwent through Storm Bay, ought to give Tasman's Head a good berth in order to avoid the islands and rocks lying off it. In proceeding northward past Fluted Cape, the most remarkable object will be the Mount Table, which is very high, and in appearance resembles the mountain of the same name at the Cape of Good Hope.

In advancing up the bay, Betsy's Island, which is high, soon appears in sight, and will enable you to steer for a small rocky islet named the Iron Pot, between which and Cape Direction there is only a boat-passage. Iron Pot Island is marked by a lighthouse, which at night exhibits a fixed light at about 70 feet above the level of the sea, and may be seen at 5 leagues off.

Having now entered the Derwent, steer about N. by W. for a low, sloping point on the larboard hand, and when abreast of it the town will open in view to the westward.

There is no danger all the way up, and ships may stand within half a cable's length on either side; the holding ground is good in every part, and the depth of water nowhere exceeds 18 fathoms. The anchorage is called Sullivan Cove, although it is merely a bend of the land; but the low, sloping point before mentioned shelters the shipping from the sea; though there is a long fetch from the S.E., which, when it blows hard from that quarter, causes a short breaking sea. BRUNY ISLAND forms the western side of Storm Bay, and to the West of this again is another channel, D'Entrecasteaux's Channel. Tasman's Head is the S.E. point of Bruny Island. There are some rocks off it called the Boreels, the S.W. of which are called the Friars, in lat. 43° 32', lon. 147° 21'. They are bare pyramidal rocks.

CAPE BRUNY is the S. W. cape of the island, and on it a lighthouse was erected in 1838. The following directions were issued with the notice:-"The top of the light upon Cape Bruny is 339 feet above high-water mark. The tower, which is quite white, is 44 feet high, and forms a good landmark by day; the machinery makes a complete revolution every five minutes; the alteration, however, from light to shade, takes place every fifty seconds, and this forms the distinguishing characteristic of the light.

"Vessels coming from the westward, unless a pilot has got on board, are recommended in no case to pass between the Acteon Reefs and the western shore; but, having arrived abreast of the Whale's Head, they are to bring that head to bear S.W. by W. W. by compass, and not open it to the southward of that bearing before the lighthouse on Cape Bruny bears N. by E. E. by compass, at which time the S. E. break, or part of the Acteon Reefs, will bear W. N. by compass, distant 2 miles, which must not be approached nearer, unless the vessel be in charge of a pilot; from that position the steering N. by W. by compass, will keep them in mid-channel, where no danger exists.

"In baffling or working winds, vessels are to keep on the eastern shore, which

may be approached boldly. Several reefs and rocks being on the western shore higher up than the Acteon Reefs, it will be necessary to approach that shore with great caution until you open Muscle Bay, and the light on Bruny is brought to bear E. S.

"The S.W. break, or part of the Acteon Reefs, bears from the Whale's Head N.E. N. by compass, distant 6 miles, and from the S.E. Cape, N.E. E. by 14 compass, distant 3 miles. Vessels working in the channel must be careful to keep the lead going, and not approach the Acteon Reefs to less soundings than 20 fathoms.

"After the vessel is above Muscle Bay, the shore on either side may be approached to half a mile."

The tides in the Derwent, and all throughout D'Entrecasteaux's Channel, seem to be very irregular; at times they rise 8 or 10 feet, at others 4 or 5 feet, and sometimes there is said to be no fall of tide for two or three days together. The stream is likewise irregular, but the ebb in general runs at the rate of 2 or 3 miles an hour. Capt. Flinders surveyed the River Derwent, in December, 1798, and in speaking of the tides he says: "In Risdon Cove the tide rises between 4 and 5 feet, which is more by at least a foot than at the entrance of the river. The time of high water is about eight hours after the moon's passage over the meridian, or one hour later than in Adventure Bay. In the narrow parts above Sullivan Cove, the tides run with tolerable regularity, and with some degree of strength; but towards the entrance of the river, the water at the surface sometimes ran down twelve hours together, and at other times as much upwards, whilst the rise and fall by the shore were at the usual periods. These anomalies were probably 'occasioned by the wind, and seemed not to extend far below the surface; for I found a counter-current at the bottom."

SECTION IV.

CHAPTER XXXVI.

THE WINDS OF THE PACIFIC OCEAN.

THIS important branch of the navigation of the Pacific is not so clearly understood, or its particulars so well defined, as they are in other parts of the world, where science or commerce have attracted a greater number of voyagers, and elicited a far greater extent of observation. In this, as in other points connected with the great ocean, its vast extent operates against the attainment of that minute acquaintance with its phenomena which is so readily attainable in the Atlantic or Indian oceans. The brief remarks, therefore, which we have to present on this point must be taken rather as generalities derived from the observed facts, or often deduced empirically, than the assertion of any certain laws by which these phenomena are governed. A general law cannot be established by a single observation, which is frequently the amount of our knowledge; and it is therefore evident that, before any system can be absolutely established, these observations must be greatly multiplied and amply discussed.

The wind-systems of the Pacific appear to be more simple than those of the Atlantic or Indian oceans. In them local causes-the configuration and effect of the land in modifying their natural characteristics-have much greater influence than in the Pacific, where the land and water exist in a very different ratio to each other.

Of the natural causes which produce those mighty currents of air, known as the trade-winds, and the less regular extra-tropical winds, much need not be said here. The explanation first given by Dr. Halley is that now considered as the correct one. After he had promulgated his theory he rejected it, and it was not acknowledged until it was revived by John Hadley.

The inter-tropical zone is maintained at a much higher temperature than those to the North and South of it, from the sun being constantly vertical over some portion. The air within that space becoming rarified, and thus specifically higher than that outside the limits, rises from the surface, while the colder air replaces it by flowing over the surface of the earth from the poles toward the equator. The warmer air must, according to this theory, be carried over these southerly and northerly currents in an opposite direction, and thus, by keeping the equilibrium, maintains a continuous circulation.