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in any part, but mostly less. The highest and most conspicuous part it a clump of mangroves fifteen feet high, about half way between the north and south extremes. The base of this island, as of all the islands, rocks, and reefs of the Abrolhos, is a calcareous limestone, of which the principal ingredients appear to be coral and shells; and it is remarkable that all the islands on the east side of the two southern groups, are merely ridges of dead coral and shells, nearly void of vegetation, whereas those on the west sides are flat blocks of limestone about five feet above water, with a covering of light sandy soil, that gives growth to a stunted and scrubby vegetation, of which, several kinds of samphire form the principal part.

From Wreck Point a narrow reef extends about a mile to the S.S.W., gradually curving to the north-west, in which direction it extends twelve miles, and forms the sea barrier of a large lagoon, of which, South Island and the reefs and islets north of it are the eastern boundary; this lagoon is thickly strewed with shoal patches of coral, and has several small islets in it. For two miles and a half from the north end of South Island is a continuous cluster of coral reefs and small islets, between which and the low coral banks, a little more than a mile to the northward is a clear passage a mile wide, with from thirteen to fifteen fathoms in mid-channel. Three miles N.N.E. of these coral banks is a small Hummock Island, having a small mound thirteen feet high at its south-eastern end; it is surrounded by a reef, which in no part extends more than a quarter of a mile off, but there is discoloured water a long half mile off the north-west end. This islet is in latitude 28° 48}-' S., and is the north-easternmost of Pelsarts Group ; between it and the patch of coral banks to the S.S.W., is a clear passage with twenty to twentyfive fathoms water.

Under the northern part of Pelsarts Group there is anchorage in fifteen to twenty fathoms, and shelter from all southerly winds, and probably a well sheltered anchorage may be found in the lagoou, between Square island and the mangrove islets, where there is from ten to seventeen fathoms water. There are several spaces of deep water in the southern part of the lagoon, where there are no doubt good anchorages, but this part of it is so strewed with shoal coral patches, that it would be a tedious business to get a ship in.

Gun islet is the north-western islet of this group; observations were taken on its south end, which place it in latitude 28° 53}-' S., and longitude 1° 53' 30' W. of Swan River. A brass 4-pounder swivel was found upon it, and several other articles that shewed it had once been the temporary retreat of some shipwrecked crew; and from the Dutch sketch of a part of these islands, shewing the place where the Zeewyk was wrecked, it is no doubt the same island to which her crew escaped.

The north-west end of the reef forming the sea barrier of Pelsarts Group, is in. latitude 2S° 51' S., between which and the southern extreme of the reefs off the next cluster, or Easier Group, is a clear passage of four miles in width, through which the crew of the Zeewyk got to sea, in a boat built from the wreck ; it has been called Zeewyk Passage in consequence.

It was sailed through by the Beagle, and appears quite free from danger; the middle of it is in latitude 28° 49,'{' S. After passing to the westward of a line between the barriers, or western reefs of Pelsart and Easter Groups, the water deepens quickly, and at eight miles distance there is no bottom with 166 fathoms of line.

The Middle or Easter Group is very similar to that south of it, the western boundary being a reef upon which the sea is alwavs breaking heavily, and the eastern limit of the lagoon is formed of low islands and coral banks, in no part over thirteen feet high, but generally under eight feet.

As at Pelsarts Group, anchorage may be had under the northern part of this, and there is a good harbour formed by Rat Island, and the reefs to the eastward of it named Good Friday harbour, where a ship will be sheltered from all sea; but as at all the anchorages amongst the Abrolhos will feel the full force of every wind, no part of the islands being of sufficient elevation to afford shelter; but as the water is perfectly smooth within the reefs, there can be no danger, providing a proper scope of cable be given. The only entrance to Good Friday harbour is from the northward, between the reefs that extend N.W.b.N. from the north end of Rat Island, and those to the eastward that extend two miles and a half from the islands that form the eastern side of the lagoon. The edges of all these reefs are well defined,—this passage is half a mile wide, and free from all impediments, until the north-west end of Rat Island bears south 38° west, (magnetic) threequarters of a mile distant, and a small white bank that is half a mile north of the north-west point of Rat Island, and generally uncovered, west 10° south, there are then some small patches of coral with very little water on them. A masthead look-out will be the best guide for keeping clear of them; with a leading wind it would be best to pass to the westward of them, keeping a good look-out for the north-eastern part of Rat Island reef, which is very little more than a sixth of a mile from these patches. You will be to the southward of them when the small while bank bears west 20° north, when a more easterly course may be steered for an anchorage. The Beagle's anchorage was with the north-west point of Rat Island, and a dry rock off the north point on, bearing west 16° south, and the north point of an island south of Rat Island south 10° west: this island appears joined to Rat Island on this bearing, and appears to be the south extreme of Rat Island; perhaps better anchorage may be had by keeping the rock and north-west point in the same bearing; but by bringing the same north point to bear more westerly, south 13^° west, both anchorages are in fifteen fathoms. The entrance to this anchorage between the reefs, may be passed by keeping the east extreme of Rat Island south 10° east, until Hearing the small coral patches, but at all times the eye will be the best guide; the observation spot at the north-east corner of Rat Island, is in 2S° 42' 28" south, and longitude 1° 57' 55" west of Swan River.

The north-east extreme of Easter Group is a small islet of dead coral five feet high, surrounded by a reef that extends half a mile off its north-east end. There is a good passage between this island and those to the southward of it, a mile and a quarter wide, with twenty and twenty-two fathoms.

The north-west point of the reefs of Easter Group is in latitude 28° 39' south, between which and Evening reef (which is the southwestern reef of the North Group,) there is a clear passage six miles wide, the middle of which is in latitude 28° 36' south.

The northern group is more extensive than either of the others, occupying a space of latitude between 28° 15£' and 28° 33'; the islands also differ from those of the two southern groups, being much larger and higher, and in most parts thickly covered with brushwood, amongst which are bushes and stunted trees of a sufficiently large growth for firewood: the principal islands of this group are the east and west Wallabi Islands, so named from the number of those animals we found npon them", they are a mile apart, but connected by a reef that is nearly dry at low water, and on the southern edge of which are the Pigeon Islands ; they are low and rocky, and covered with brushwood and shrubs. On the north-easternmost of these islands the observations were made which place its north end in latitude 28* 27' 21" S.; variation 4° 10' westerly.

A good port is formed between east Wallabi Island and the low islets and reefs south and south-east of it, named Recruit harbour: it is easy of access by bordering towards the south east side of east Wallabi Island, which may be approached within a sixth of a mile. After passing Fish Point, which is the north-east point of the island, and may be passed at an eighth of a mile distant, stand on to the southward until the bare-topped sand hill at the south end of west Wallabi Island bears S.W. 5 W. (mag.) it will then be on with the north end of the northeast Pigeon Island ; steer for it, till Flag Hill bears N. £ E., then a remarkable sand hill on the north-western side of the island, will first be open to the westward of Eagle Hill. From this steer south, until the north end of the Pigeon Island bears west, and anchor in ten to twelve fathoms, soft bottom, and about one-sixth of a mile from the reefs; there will be only one point open between Fish Point and the north-west point of the reef that forms the east side of the anchorage.

This is a very secure anchorage, but from its contracted size, a ship should moor. In standing for the. anchorage after passing Fish Point, some patches of coral will be passed, with five and five and a half fathoms water on them, but there does not appear to be less; they may be avoided by a masthead look-out, which is at all times advisable when sailing amongst coral reefs. Flag Hill is fifty feet high, and may easily be known by its being the highest part of the island, and towards the norlh-east end.

Three miles and a half east of Fish Point, or four miles E. i N. from Flag Hill, is the north-east reef, which should be carefully avoided, as at times there are long intervals when it does not break; the water appears to be deep close to it, excepting on its south-west side, where there is ten fathoms rocky, a mile off.

With the exception of the Wallabi Islands and North Island, all the other islands of this group are very low, being merely banks of dead coral, the highest of which is only eight feet above the sea. The easternmost islet of this group bears east 28° south, (magnetic) and is distant four miles and a half from Flag Hill;—from this islet the north-east reef bears north two miles and a half, and the passage between them appears clear.

North Island, (which is the northernmost island of Houtmans Abrolhos,) bears north 40° west, (magnetic) from Flag Hill, and is distant ten miles and a half, in which space there may be a passage to sea, but as there appeared to be so many straggling rocks, and the western limit of the barrier is at such a distance from the islands, that if a passage does exist, it can be but narrow, and not over safe. For four miles south of North Island is a continued reef with heavy breakers, and which may probably extend to a greater distance, towards the reef off the north-west part of west Wallabi Island, and as these reefs have been traced five miles to the north-west of that island, little space is left for a passage between them. No doubt there is an opening, on account of the long swell that rolls in between them from the westward, but it would not be prudent to risk a ship while any doubt exists.

North Island is of circular form, three miles in circumference, and with the exception of a small sandy bay on its north-east side, is surrounded by reefs; the only anchorage is off this bay, about threequarters of a mile, or a mile from the beach, in a very indifferent berth.

This island is similar to the Wallabi Islands, the base of rock being covered with a sandy soil that gives growth to a stunted scrub; the centre of the island is perfectly flat, and encircled by a marginal ridge of sand hills, the highest of which is forty-two feet; it is at the southwest part of the island, and has been named Record Hill, because a bottle, containing a paper, shewing the date of our visit, was deposited there. The observations were taken on Latitude Hill, on the east side of the island, the summit of which is in latitude 28° 16' 16" S., and longitude 2° 8' 57" west of Swan River.

From the north end of this island, the reef extends as far as 28° 15' 30", which is the extreme northern limit of the Abrolhos: to the westward of the island, all appears clear beyond a mile and a half, and to the eastward of the island the reef does not extend over half a mile.

Soundings may be had at a greater distance from the reef off the western side of this island, than of any of those to the southward.

When the centre of North Island bore east, four miles and a half, we found thirty fathoms, coral, and with the centre of the island N. 70° E., distant seven miles, forty-two fathoms coral, to the westward of that it deepens quickly.

There does not appear to be any outlying dangers round the Abrolhos, and with the exception of Snapper Bank, there is a very uniform depth of water, from twenty to twenty-five fathoms between the different groups, and in the space between them and the main land it is rarely over thirty fathoms.

Snapper Bank, which is the only patch of shoal water that was found detached from the different groups, is N. 15° W. (mag.) from Small Hummock Island of Pelsarts Group; its south end is distant five miles and a half; it extends a mile and three-quarters to the northward, and is three-quarters of a mile wide; the least water found upon it was six fathoms. From this bank Small Hummock Island is just visible from the deck, at an elevation of fifteen feet.

The only information respecting Houtmans Abrolhos, that has ever been hitherto made known, being merely extracts from the journals of those who had suffered shipwreck upon them, it is not to be wondered at, if such accounts have had the effect of warning all navigators from them, hence sc long a time has elapsed without their exact limit having been ascertained. They lie parallel to that part of the coast of New Holland, opposite to them, (nearly N.N.W. and S.S V..,) the southern limit of the reef off South Island, is in latitude 29° 00£' S., and the northern extreme of North Island reef is in 28° 15 j'; the western part of which is in longitude 2° 11' west of Swan River (this is the westernmost part of the Abrolhos, and the eastern limit (which is Small Hummock Island,) is 1° 42' 30'' west of the same meridian.

The Abrolhos may be considered as a place of refreshment, inasmuch as fish, of an excellent quality may be taken with a hook and line in any quantity, chiefly snapper and rock fish, which prove a valuable spa slock. Wallabi may be had on the islands of that name, where fuel may also be procured, and water may probably lie found in many places during rains, but cannot be depended upon as a certainty, owing to the porous nature of the rock. A small quantity was found on the Wallabi Islands in May, but of an indifferent quality.

These islands might prove a welcome retreat to vessels employed in whaling on the west coast of New Holland; they generally carry sufficient water for their voyage, therefore would only require some refreshment for their crews, and this might be procured without the trouble of lowering a boat, by merely anchoring the ship near the reefs, on the east side of the islands, or between the different groups, where in a few hours a sufficient supply of fish for immediate use, and for salting may he taken.

There is no danger beyond the breakers that form the western barrier, and as the weather is generally clear enough to admit of a meridian altitude being observed, the ship's latitude may always be known, which with a common look-out, is sufficient to keep her clear, and no dangers exist that are not easily seen from the mast-head; the only drawback to anchoring under the Abrolhos, is the depth of water, but excepting when moored in confined places, the stream- anchor with a long scope of bower chain, will be found quite sufficient. The Beagle very rarely let go a bower anchor.

The prevailing winds at the Abrolhos are southerly, and the weather is usually fine; there is no stream of tide to affect a ship,and the range is under three feet. The current is influenced by the wind, and consequently is generally setting to the northward, varying in direction amongst the islands; its velocity depends upon the strength of the freeze, but is rarely over a knot an hour.

Notes On The Mouth Of The Yang-tse-keang.By Capt. R. D. Bethunc, 1LM-S- Comcay.

In our last number, we announced the publication of Capt. R. D. Bethune's survey of the mouth of this great river, in one of the series of charts of the coast of China, supplied by the Admiralty, for the use of her Majesty's ships, and placed in common with all the Admiralty charts,

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