Chapter XIII: Appendix (1)

CONTAINING

CHARTS

OF THE GULF OF PE-CHE-LEE, THE WEST COAST OF COREA, THE GREAT LOO-CHOO ISLAND, NAPAKIANG ROADS, AND PORT MELVILLE: WITH BRIEF EXPLANATORY NOTICES.

TABLE OF OBSERVATIONS

MADE WITH DR. WOLLASTON'S DIP SECTOR: WITH AN ENGRAVING, AND A DESCRIPTION OF THIS INSTRUMENT, AND DIRECTIONS FOR ITS USE.

METEOROLOGICAL JOURNAL,

FROM JULY TO NOVEMBER 1816, WHILE THE SHIPS WERE IN THE YELLOW AND JAPAN SEAS.

ABSTRACT OF THE LYRA'S VOYAGE,

FROM LEAVING ENGLAND TILL HER RETURN; SHEWING THE DISTANCE BETWEEN THE DIFFERENT PLACES AT WHICH SHE TOUCHED, AND THE TIME TAKEN IN PERFORMING EACH PASSAGE.

GEOLOGICAL MEMORANDUM;

BEING A DESCRIPTION OF THE SPECIMENS OF ROCKS COLLECTED ON THE SHORES OF THE YELLOW SEA, COREA, LOO-CHOO, MACAO, AND THE LADRONE ISLANDS.

CHARTS

OF THE

GULF OF PE-CHE-LEE, THE WEST COAST OF COREA, THE GREAT LOO-CHOO ISLAND, NAPAKIANG ROADS, AND PORT MELVILLE.

WITH BRIEF EXPLANATORY NOTICES.

_East of Greenwich_]

NOTICE EXPLANATORY OF A CHART

OF

THE SOUTH SIDE OF THE GULF OF PE-CHE-LEE, YELLOW SEA.

[Sidenote: First meridian used in constructing the chart.]

In constructing this chart, I have assumed the longitude of the fort at the mouth of the Pei-ho to be 117º 49' east of Greenwich, or 11' west of the place where the squadron lay at anchor. From this the difference of longitude was measured by two chronometers. The latitudes were ascertained by frequent observations of the stars, as well as of the sun.

[Sidenote: Aspect of the south and south-west coasts.]

[Sidenote: Soundings.]

The coast on the south and south-west sides of this Gulf is very low, resembling, in this respect, the shore at the entrance of the Pei-ho, or Pekin river, where it is uniformly low and sandy; occasionally a few houses are to be seen, and also square mounds or buildings like forts, but generally, a low white beach is all that can be discovered. The coast is not visible till within about three leagues distance, and the eye elevated eighty feet from the sea, which is the height of the Lyra's foretop-gallant yard. The depth of water when the land first came in sight, was generally five fathoms; at some places only four fathoms, and at the very bottom of the Gulf, it could not be discerned till in three and a half fathoms. It may be said generally, that at ten miles distance the soundings are from four and a half to six fathoms; at twelve miles, from six to eight fathoms. There is a wonderful uniformity in the depth from the Pei-ho round to the south-east corner of the Gulf; the bottom is mud, sometimes a little gritty, particularly towards the southern parts.

[Sidenote: Colour of the water.]

The colour of the water was mostly of the same dirty yellow or green which was observed off the Pei-ho, but we did not observe any red coloured water, as was frequently noticed at that place; at the bottom of the Gulf, indeed, there were several changes in the colour of the water, accompanied by long lines of foam, indicating, it would seem, the vicinity of a great river.

[Sidenote: Tides on the western side of the Gulf.]

On the west side of the Gulf the ebb tide runs to the south-east by south, and the flood north-west by west; the periods are very regular, being generally about six hours: they vary, however, in rapidity. As we anchored on the flood we were enabled to measure its velocity; as we got deep in the Gulf it decreased: at the Pei-ho it frequently ran two and two and a half knots, but far south it was sometimes hardly perceptible; it is worthy of notice, too, that the perpendicular rise and fall decreased from ten feet off the Pei-ho, to one, or at most two feet, in the bottom of the Gulf.

[Sidenote: Bottom of the Gulf.]

The most southern point of our track was 37º 15' north; at this time we could perceive the low coast stretching to the east and west; the distance it is difficult to assign very accurately, but it was probably seven or eight miles, for with a glass we could perceive a number of people on the shore. I took great pains to ascertain the latitude stated above, by the meridian altitudes of several stars; the longitude is 1º 39' east of the Pei-ho, or 119º 28' east of Greenwich.

[Sidenote: South-eastern side different from the opposite.]

The coast from the south-west corner of the Gulf to the peninsula of Teu-choo-foo, is of a totally different character from that opposite to it, for it is high, and well marked: a range of mountains stretches from south-west to north-east, at the distance of three or four leagues inland; their outline is peaked, and they are intersected by deep ravines without any verdure; the summits are also barren.

[Sidenote: Mount Ellis.]

One of these mountains is very remarkable, having two peaks or paps by which it can be distinguished at the distance of fifty miles, and bears the same aspect when viewed from all parts of the Gulf. It lies in 37º 6' north, and 2º 11' east of the Pei-ho, or 120º east of Greenwich. It has been called Mount Ellis, in honour of Mr. Ellis, the third commissioner of the Embassy.

[Sidenote: Aspect of the coast.]

[Sidenote: Jane's Isle.]

[Sidenote: Douglas Island.]

Between this range of hills and the shore, there is a lower belt of elevated ground in a state of high cultivation, covered with many towns and villages, and interspersed with scattered trees and several extensive woods; the ground, too, presents a varied surface, so that the whole offers a pleasing contrast with the rugged land behind. There are two small islands on this line of coast; the southern one lies in 37º 21' north, and 2º 5' east of the Pei-ho; the other is in 37º 28' north, and 2º 19' east of the Pei-ho.

[Sidenote: Dangerous shoal.]

There is a dangerous shoal about five leagues off the shore, abreast of these islands, upon which the Lyra nearly struck at midnight on the 17th instant. When at anchor just outside the shoal, the south island bore south 20º east, and the other, east 21º south; on the shoal there was two and a half fathoms, hard bottom. It seems to extend in a north and south direction, and is very narrow. It lies in 37º 32' north, which I ascertained by altitudes of the pole star, under favourable circumstances. It is 1º 58' 30" east of the Pei-ho.

[Sidenote: Soundings and tides.]

The soundings on this side of the Gulf are somewhat deeper than on the other, but not so deep as might have been expected from the bold nature of the land. The ebb tide runs to the north-eastward, and the flood into the Gulf.

[Sidenote: Winds.]

[Sidenote: Melville Point.]

[Sidenote: Teu-choo-foo city.]

The wind was south-east and quite light, from the 11th August to the 17th, when it shifted to north north-east till about eight P.M. when close in shore near the southern of the two islands; it then blew off, with all the appearance of a regular land breeze. On the 19th it blew a gale of wind from the north-east, with a short, high sea; during the gale we lay at anchor off a remarkable point, connected with the main land by a low sandy neck; the ground felt soft to the lead, but it was probably rocky under the mud, as both ships lost a bower anchor by the cables being cut. This point lies in 37º 42' north, and 2º 35' east of the Pei-ho. We found the city of Teu-choo-foo to lie in 3º 4' east of the Pei-ho. The latitude observed in Teu-choo-foo roads was 37º 53' north, and the longitude 2º 54' east of the Pei-ho. The western Meadow Island bearing north.

[Sidenote: Cheatow Bay.]

The latitude of a small island at the north-east corner of the Bay of Cheatow or Zee-a-tow, was determined by the sun's meridian altitude on shore, to be 37º 35' 52" north, and longitude east of the Pei-ho 3º 45', or in 121º 34' east of Greenwich.

[Sidenote: Oei-hai-oei.]

The latitude of Oei-hai-oei was observed on shore to be 37º 30' 40" north, and lies 4º 25' east of the Pei-ho.

[Sidenote: Variation of the compass.]

The variation of the compass in the Yellow Sea was found to be 2º 16' westerly.

The rise and fall of the tide at the anchorage of the squadron off the Pei-ho was twelve feet. It was high water at full, and change at III. The flood tide runs to the west-south-west, and the ebb generally about east and east-south-east. Its strength and direction are a good deal influenced by the prevalent winds.

NOTICE TO ACCOMPANY THE CHART OF THE WEST COAST OF COREA.

[Sidenote: Inadequate time allowed for so extensive a survey.]

This chart extends from 34º to 38º north latitude, and from 124º to 127º east longitude. The time of our stay on the coast being only nine days, no great accuracy is to be expected, and this chart pretends to be little more than an eye-draught, checked by chronometers and meridian altitudes of the sun and stars. Under circumstances of such haste, much has unavoidably been left untouched, and what is now given is presented with no great confidence.

[Sidenote: General remarks on the methods followed in the survey.]

What follows is extracted from notes made at the time by Mr. Clifford and myself. The longitudes by chronometer have all been carefully recomputed, and the greatest care was taken in ascertaining the various latitudes. The true bearings are in every instance set down, the variation being allowed for at the moment. The variation of the compass recorded in this notice, was determined by two azimuth compasses, and the method recommended by Captain Flinders, of repeating the observations by turning the compass first one way and then the other, was invariably followed.

[Sidenote: The ships leave China.]

[Sidenote: Make the coast of Corea.]

[Sidenote: Sir James Hall's group.]

[Sidenote: Anchorage on the south side of an island.]

His Majesty's ships Alceste and Lyra, after quitting the port of Oei-hai-oei, which is in latitude 37º 30' 40" north, and longitude 122º 16' east, on the north coast of Shantung Promontory, stood to the northward and eastward till in latitude 38º north, and then ran to the eastward. On the morning of the 1st of September, 1816, we saw the land, bearing about east. By sights with chronometer on the meridian of these islands, we ascertained that the west end of the northern one lies in 124º 44-1/2' east. The latitude of the south end of the eastern island was ascertained by meridian altitude of the sun to be 37º 44-1/2' north. There is a rocky white islet off the west end of the middle island. We had from twenty to thirty fathoms on rounding the south-west end of the islands, but on the south side of the southern one there is a bight with seven fathoms, black sand in the centre: here we anchored. There is good anchorage all over the bay, which is sheltered from all winds except between west south-west and south-east, being open to the southward. There are two villages here. From the top of the highest peak on this island, which is about seven or eight hundred feet high, we could discern the main land of Corea, high and rugged, stretching north north-west and south south-east, distant from eight to ten leagues. Along the coast abreast of us there were seen many islands. The channel between the middle island of the group and the one we were upon appeared clear and broad; but the northern and middle islands seemed connected by a reef which shews above water at several places.

[Sidenote: Character of the inhabitants.]

The inhabitants were suspicious and unfriendly: we saw some cattle and many fowls, but neither money nor any thing else that we had could induce them to part with either.

[Sidenote: Lose sight of the coast.]

In the evening we weighed and stood to the southward; next morning there was no land in sight. At noon we were in longitude 124º 47' 52" east, and latitude 36º 44-1/2' north, no land in sight. We hauled in shore to the eastward, and anchored in the night in deep water.

[Sidenote: Group of five islands.]

[Sidenote: Bearings.]

3rd of September.--Weighed at 3.30 and stood in shore; at 7.45 A.M. we were due south of the western of a group of islands. Many sights were taken as we passed to settle the place of this group: it lies between 125º 42-1/2' east, and 125º 57-1/2' east, and in latitude 36º 44' north. After passing this group we stood to the south-east towards a vast cluster of islands: at noon, when we were just entering the cluster, the latitude was observed 36º 18' 21" north, and longitude 126º 10' east. The south-west extreme of the islands bore south 40º west. There were eight islands near us between south-east and south-west, and a high bluff dark rock south one-quarter east, four miles: and on the main land a very high hill, east 19º north. When we had got well among the islands it fell calm, and we anchored in eight and a half fathoms. It remained calm during the night.

[Sidenote: Run among the islands.]

4th of September.--Weighed on a breeze springing up, and stood in shore. Observed in 36º 13' north, longitude 126º 30' east; at this time the following bearings were taken.

[Sidenote: Bearings.]

A remarkable peak on the main land, east.

High mountain on the main land, east 38-1/2º north.

White cliff on the east end of the fourth island to the left of the wide entrance into the cluster, north.

Small round island, north 30º west.

Another, north 35º west.

Extremes of a large bluff island from north 38º west, to north 32-1/2º west.

Rock, north 72º west.

Outer island, north 75º west.

Extremes of the outer cluster, from north 77-1/2 west, to west 1º south.

Large island, from west 14º 30' south, to west 18º south.

[Sidenote: Basil's Bay.]

[Sidenote: Unsocial disposition of the inhabitants.]

These islands being within from ten to fifteen miles, were laid down by estimated distances, but it was quite impossible to assign places to the immense number of others which stretched away to the south and south-east, as far as the eye could reach. We stood in shore for the purpose of discovering whether there was any place of shelter in the main land, but in general it proved shallow and unsafe. At length we discovered a bay which promised shelter, but on running into it, the depth was found not to exceed three or four fathoms. This bay is open towards the south, and is formed by a curved tongue of land on the north and west. The longitude of the south end of this point is 126º 42' 22" east, and latitude 36º 7' 38" north. We remained here during the night, and the forenoon of the 5th. The natives came on board, but made great objections to our landing.

[Sidenote: Tides.]

The tide rose and fell fifteen feet and a half; it was low water at 8 P.M., and high water at 2.30 A.M. This was two and a half days before full moon.

The Alceste's boats were sent to sound in the eastern quarter, but they found shoal water every where.

[Sidenote: Proceed to the south-westward.]

5th of September.--At 11 A.M. we got under weigh and stood to the south-west among the islands, carrying seven, eight, nine, ten, to fifteen fathoms, and occasionally deepening to seventeen fathoms. At 4.45 we observed in longitude 126º 24-1/2' east, and latitude 35º 52' north at this time.

[Sidenote: Bearings.]

Two islands bore north half east, seven miles.

A remarkable small black island, west 32º, north four miles.

Another, west 22º north, seven miles.

A range of islands, from east 10º north, to east 16º south.

A long island, from south 25º east, to south 11º east.

The islands off which we anchored on the 2nd instant bearing about north 10º west.

Two islands, from south 16º west, to south 25º west.

[Sidenote: Main land.]

The main land from south south-east to north-east, high and rugged.

We had a sea breeze to-day, and fine weather. Variation 2º 10' westerly. We ran on by moonlight till 11 P.M., and then anchored among the islands. Latitude, observed by Polaris 35º 26' north. Longitude, at anchor by chronometer next morning 126º 23' 22" east. From this spot the main land was seen from east 12º north, to south 20º east.

[Sidenote: Bearings.]

A rock, west 7º south, four miles.

An island, from west 15º north, to west 31º north, 4-1/2'.

Three islands, extending from west 36º south, to west 45º south, 3'.

Two distant ones in the same direction.

Cluster of islands, from west 64º south, to west 84-1/2º south.

Large island, north 12º west, ten or twelve miles.

A cluster of islands, from north 15º east, to north 28º east.

Two distant islands, north 32º east.

Two others, north 42º east.

[Sidenote: Channels between the islands generally deep.]

6th of September.--Weighed and stood to the southward. At noon observed in 35º 17' north, longitude 126º 28-1/2' east, being then in the centre of a semicircle of islands, extending from north-east to south-east and south-west. During the forenoon the flood tide set strong to the north north-east against us. Most of the channels between the islands were deep, but to-day we tried one which had not more than five and a half fathoms. At 4.30. took sights, when a long bluff island bore east north-east a quarter of a mile. Longitude 126º 6' 37" east; latitude 35º 6' north. This island is the most westerly of the range of islands which lie between the latitude 35º and 36º north. High and connected land was faintly discernible to the eastward. The soundings were generally from nine to fifteen fathoms, deepening in most cases on approaching the bluff islands.

[Sidenote: Flood tide runs to the northward.]

[Sidenote: Windsor Castle.]

[Sidenote: Bearings.]

7th of September.--We anchored last night about ten o'clock in seventeen fathoms; the flood tide had made; it ran north nearly three miles an hour, till four A.M. when we got under weigh, and drifted fast to the southward with the ebb. At 9.30. got sights, which gave longitude 125º 52' 45" east, latitude 34º 42' north; at this time a very remarkable hill on an island bore east 8º south; it has the appearance of a turret or large chimney. The other bearings from this spot were--

Western extreme of a large island stretching west north-west, and east south-east; north 27º, east 4 or 5'.

Round rock, north 18º east, 8'.

Cluster of islands from north 50º west, to north 74º west.

Round bluff small island, west 9º south.

Large island, west 42º south, 7 or eight leagues.

Two small distant islands, west 53º south, 10' leagues.

Small island, south 11º east.

[Sidenote: Soundings.]

[Sidenote: Variation of the compass.]

Extreme of distant land, south 37º east: besides, as usual, innumerable distant islands. The flood tide made against us between ten and eleven. The soundings this morning have been from twenty-three to nineteen fathoms. The weather extremely hot and the water smooth. The ebb made about four, and there being no wind, it carried us rapidly towards some rocks joining two islands. We anchored in twenty-one fathoms. The variation of the compass 2-1/2º westerly. The bearings at anchor this evening were as follows:

[Sidenote: Bearings.]

Small island, south 3º 22' east.

Large island, from south to south 20-1/2º east.

A small island, south 22º east.

Another, south 28-1/2º east.

High bluff island, south 31º east.

Island from south 9º east, to south 18º west.

Sharp peaked rock, south 25º 40' west.

Island from south 63º west, to south 65º west.

Distant island, from south 63-1/2º west, to south 66º west, nine or ten leagues.

Distant small island, west 1º 10' north, seven or eight leagues.

[Sidenote: Bearings.]

Distant island, from west 6º 39' north, to west 9º north, formed of one large flat space and five hummocks, eight or nine leagues.

Island, west 28º 50' north.

Large island, from west 31º north, to west 38º 19' north.

Round bluff island, off which we observed at noon to-day, west 39º 52' north.

Distant small island, west 44º 28' north, four or five leagues.

Large island, from west 71º north, to west 81º 30' north.

An island, afterwards called Thistle Island, south 79º east, to east 14º 52' north, besides numberless islands, in thick clusters, extending as far as the eye could reach, in the north-east and east quarters. In the afternoon a boat went inside Thistle Island, and reported that there was a clear anchorage.

[Sidenote: Sail into Murray's Sound.]

[Sidenote: Latitude observed on shore.]

[Sidenote: Longitude.]

[Sidenote: Tides.]

[Sidenote: Variation of the compass.]

8th of September.--At noon we weighed and sailed round the north end of Thistle Island, carrying seventeen fathoms, till the north end bore south; we then shoaled to ten and eleven, and one cast nine fathoms. On rounding the island we steered south, and anchored in eleven fathoms, soft bottom, about four hundred yards from the middle part of the island. The islands at this place are so situated as to form a capacious and secure anchorage, with passages among the islands in all directions. The latitude observed with an artificial horizon on shore, was 34º 22' 39" north; longitude by mean of two chronometers, agreeing nearly, 126º 2' 52" east. The tides run at the springs at the rate of three and four knots, the flood to the north north-east; the rise and fall is fifteen feet. Strong eddies are felt among the islands. The variation of the compass is 2º 30' westerly.

[Sidenote: Appearance of the Amherst Isles, from the top of a peaked island.]

On the 9th of September Captain Maxwell and a party went to the summit of a high peak, on an island to the south-east of the ships, in latitude 34º 20' north, and longitude 126º 6' east. From this spot, elevated about seven or eight hundred feet above the sea, the view of the islands was very striking: we endeavoured to number them, but our accounts varied, owing to the difficulty of estimating the number in the distant groups; it will serve, however, to give some idea of this splendid scene, to say that the lowest enumeration gave one hundred and twenty islands.

Many of these islands are large and high, almost all are cultivated, and their forms present an endless diversity.

High land was seen to rise above the distant islands in the east and north-east; this probably was the main land of Corea, for it seemed more extensive and connected than any group of islands we had seen.

[Sidenote: Difficulty of estimating the number of islands on this coast.]

We had now ran along upwards of two hundred miles of this coast, and at every part which we approached, the islands were no less thickly sown than here; so that our attempts to enumerate them all, or even to assign places on the chart to those which we passed the nearest to, became after a time quite hopeless.

[Sidenote: Winds and weather.]

During our stay upon the coast of Corea, between the 1st and 10th of September, the winds were principally from the northward; the weather was moderate and clear; and occasionally calm during the heat of the day.

[Sidenote: Barometer and thermometer.]

The barometer rose and fell gradually between 29. 78. and 29. 98. The thermometer was never above 82º, and never, even at night, under 72º For further details respecting the winds and weather, see the Meteorological Journal.

_Surveyed in H.M. Sloop LYRA by Captain Basil Hall_

1816]

NOTICE TO ACCOMPANY THE GENERAL CHART OF THE GREAT LOO-CHOO ISLAND, AND THE CHARTS OF NAPAKIANG, AND PORT MELVILLE.

[Sidenote: Different names of this island.]

This island is called Loo-choo, and sometimes Doo-choo, by the natives. In our maps it is variously written, but mostly Lekayo: the Chinese know it by the name of Low-kow. The spelling used by Mr. Horsburgh in his directions, Lieou-kieou, or Lieu-chew.

[Sidenote: Geographical limits and general aspect.]

The island lies between 26º 4-3/4' and 26º 52-1/2', north, and between 127º 34' and 128º 18' east, being very nearly sixty miles long in a north-east direction, and preserving a tolerably uniform breadth of about ten or twelve miles. The north end is high and bold, with wood on the top of the hills. The north-east coast is also abrupt, but quite barren. The south-east side is low, with very little appearance of cultivation. The south, south-west, and western faces, particularly the two former, are of moderate height, and present a scene of great fertility and high cultivation: it is to this quarter that the mass of population have resorted. The north-west side is generally rugged and bare.

[Sidenote: Deep bay.]

[Sidenote: Barrow's Bay.]

There are two deep indentures, one on each side of the island; that on the west has at least one hundred fathoms depth, and appears to have no coral in it: while the eastern bight is extremely shallow, and is not only skirted by a broad fringe of coral, but has reefs in the centre; and these last are very dangerous, for they give no warning either by breakers or discoloration of the water, or by soundings: and this remark will apply generally to all the reefs round this island, rendering the navigation, particularly at night, very dangerous.

[Sidenote: General caution respecting coral reefs.]

[Sidenote: Sugar Loaf or Eegooshcoond.]

The most remarkable headland is the island called by Captain Broughton the Sugar Loaf, and by the natives Eegooshcoond (tower or castle); it can be seen distinctly at the distance of twenty-five miles when the eye is elevated only fifteen feet. It is a high conical mountain, varying very little in its aspect when viewed from different quarters: as there is no other peak like it on or near this island, it cannot be mistaken. The latitude of the peak is 26º 43' north; and I have reason to believe that this is within one mile of the truth. Its longitude is 127º 44', or 6' east of the observatory at Napakiang, by two chronometers. The base of the cone and one-third of the way up is covered with houses; and the whole island has the appearance of a garden. When nearly on the meridian of the Sugar Loaf its top seems rounded off.

[Sidenote: Two safe anchoring places.]

[Sidenote: Geographical position of Napakiang.]

There are two places where ships can ride in safety, Napakiang Roads on the south-west, and Port Melville on the north-west side of the island. The first of these is the one in which his majesty's ships Alceste and Lyra lay for upwards of a month. By means of a base of 1319 feet on a coral reef, which dried at half ebb, we were enabled to make the survey which accompanies this notice. The latitude of the observatory was determined to be 26º 13' 34" north, the mean of three meridian altitudes of the sun by a sextant of Cary's, and five by a circle of Troughton's, the extreme difference being 20". The longitude is 127º 38' east; this was ascertained by measuring the difference of longitude between the observatory and Lintin Island off Canton river in a run of six days; on which occasion two chronometers on board the Lyra gave within one mile the same difference of longitude, viz. 13º 50', with that shewn by two others on board his majesty's ship Alceste; the longitude of Lintin being 113º 48' east of Greenwich. The longitude, by lunar observations, is 127º 37' 28". The plan of Napakiang roads will be found sufficient without many directions for ships wishing to enter it. The principal danger lies in the outer reefs, which do not show when the weather is very fine and there is little swell; on such occasions a boat ought to go a-head at least a quarter of a mile, and the ship should put about instantly upon approaching the reefs, which are every where bold. A ship coming from the westward ought to steer between the north-eastern of the group of high islands to the south-westward, and a low green island with extensive reefs to the northward, in latitude 26º 15' north. On passing which she should haul up east by south, giving Reef Island a birth of at least a mile.

[Sidenote: Plan of Napakiang.]

[Sidenote: Directions on approaching Napakiang.]

[Sidenote: Reef Island.]

[Sidenote: Directions for entering Napakiang roads.]

_on the S.W. Side of the_ GREAT LOO CHOO Island

_Laid down from actual survey by Captain Basil Hall R.N. H.M. Sloop LYRA_ 1816]

[Sidenote: Capstan Rock.]

[Sidenote: Best anchorage off the mouths of two rivulets.]

[Sidenote: The northern entrance.]

On approaching the main land a conspicuous wooded point will be seen, having rocks on its summit like the ruins of an abbey; this forms the south side of the anchorage, and is considerably more to the westward than the north-east side. The harbour of Napakiang will soon be seen at the south side of the bay; steer directly in for this, giving Abbey Point a birth of half a mile, and when directly between the south end of the outer reefs and Abbey Point haul up east by north. There is a very remarkable rock on the south-east side of the anchorage resembling the head of a capstan. It would be safest to anchor when this bears about south-south-east half a mile at most, in order to avoid a dangerous coral tongue, which lies north a little easterly from it, three-quarters of a mile; but as this anchorage is exposed, the ship may proceed farther in as soon as the exact place of the reef has been ascertained by boats; and if she proposes staying any time, she may warp into Barnpool, taking the precaution of placing a boat on each side of the entrance. There are two rivulets at this place, and probably the best anchorage is off their mouths, the bottom consisting of the mud brought down by the stream. There is a well on the eastern side supplied by a spring, and there are landing places at the entrance of both harbours. There is a safe passage between the reef, on which the base was measured, and the outer ones. The Lyra passed through this three times; and if the object is to go to the northward it ought to be followed, provided the wind will admit of steering north and two points on each side of it. The leading mark for going by this passage is Capstan Fort or Rock, on with a remarkable nose formed by the trees on the highest distant land; these are on when they bear about south by east half east. It would certainly not be advisable for a stranger to enter by this passage, but he may run on coming from the northward along the shore at the distance of two or three miles till Reef Island bears west, and then he should look sharply out for the reefs, keeping outside them till near Abbey Point, then act as before directed. On running down towards Napakiang from the northward a remarkable bluff table land will be seen to the southward of Abbey Point. The west face of Abbey Point ought to be kept just on with the east end of the table land; this will take you further out than is absolutely necessary; but it is safe; and when Reef Island is just on with the northern of the group of distant islands you will be exactly off the north entrance.

[Sidenote: Appearance of land in coming from the northward towards Napakiang.]

[Sidenote: Not to be attempted by a stranger.]

[Sidenote: Dangerous coral reef about four leagues south-west by west from Napakiang.]

On coming from the southward the only danger that lies in the way is a coral reef even with the water's edge; it is of a circular form, and at low water several rocks shew on it. On every occasion that we passed the sea broke high upon it; but from what we saw of other similar reefs, it seems very probable that when the water is smooth it will give no warning: it is about eight miles west, 15º north of the extreme south point of the island, and lies in latitude 26º 7' north, and longitude 127º 26' east of Greenwich.

[Sidenote: Port Melville.]

[Sidenote: Directions to approach it, and to anchor previous to entering the harbour.]

Port Melville is on the north-west side of the island. A ship wishing to enter it ought to make the Sugar Loaf Peak, and steer between it and the cluster of islands to the northward, directly for the bottom of the bight, which lies between the Sugar Loaf and the north end of the island; here Herbert's Island will be seen close to the shore, run in towards its western end, anchor when it bears east one-third of a mile, and the Sugar Loaf west one-quarter north, barely shut in with a low dark green point of land; here you will have from seventeen to twenty fathoms.

[Sidenote: Boats should be sent to buoy the channel.]

The entrance of the harbour is narrow, and ought not to be attempted without previous examination by the boats of a ship wishing to enter it. With a very little trouble the passage might be buoyed: a large ship will probably find it expedient to warp in and out.

[Sidenote: Eye-draught of Port Melville.]

The eye-draught, with the directions on it, render much further notice here superfluous. The harbour is secure, and sufficiently capacious for a numerous fleet. It extends in a north and south direction for about two miles, varying in breadth and form in a very remarkable manner; at the lower or north end there are two basons of a circular form, and have from nine to fifteen fathoms, soft bottom; these are about one-third of a mile across. At some places the steep rocks which form the banks approach within an hundred yards of one another; here the water is sixteen, eighteen, and twenty fathoms. There are many fine coves, some with shelving shores, and others steep-to. Every part of the harbour is secured from the sea, and many parts from all winds: it is well calculated for the re-equipment of ships, for it is not only secure as an anchorage, but offers conveniences for landing men and stores, and also for heaving down or careening a ship.

[Sidenote: Villages of Cooee and of Oonting.]

There are several large villages on the shores of an extensive bay, communicating with the sea to the north-eastward, at the upper or south end of the line of harbours, and one called Oonting on the west side of the lower harbour; there is another of some extent, on the south side of Herbert's Island, called Cooee.

By permission of Captain Maxwell, I have named this excellent harbour, Port Melville, in honour of Lord Viscount Melville, First Lord of the Admiralty.

From the top of a range of hills which we ascended, rising on the south side of the upper bay of Port Melville, we could see the south-west corner of the great western bay, the whole range of Port Melville, and the coasts adjacent.

[Sidenote: Geographical position of Port Melville.]

The latitude of Herbert's Island, which lies directly off the entrance of Port Melville, is 26º 42-2/3' north, by meridian altitude of the sun observed on shore. Its longitude, which is also the longitude of Port Melville, is 127º 55' east, or 17' east of Napakiang observatory. The Sugar Loaf bears from the centre of the island, west 4-1/2º north, about ten miles.

[Sidenote: Coast skirted by coral reefs.]

As the whole part of this coast is skirted by dangerous coral reefs, the greatest attention should be paid to the lead, and the ship ought to be put about the instant that the water shoals to eight, seven, or six fathoms. On running in for the west end of Herbert's Island, on the morning of the 11th of October, we passed over a coral ledge having nine fathoms on it. The west point of Herbert's Island bore at this time south 8º 40' west, distant four or five miles. Before and after passing this we had from thirty to sixty fathoms; whether it was shoaler than nine fathoms at any place, was not ascertained, but the circumstance is deserving of notice, and ought to teach the necessity of constant vigilance, when near coral reefs.

[Sidenote: Montgomery islands.]

The cluster of islands to the northward of Port Melville lies between 26º 54' and 27º 4-1/2' north, the north end of the northern one being in longitude 127º 57' east, or 19' east of the observatory. It does not appear that there is any good anchorage about them; and there are dangerous reefs off the south and south-western ones.

[Sidenote: Hope Point.]

The north end of the Great Loo-choo lies in 26º 52-1/2' north, and this is probably within one, or at most two miles of the truth. We observed in 27º 00' 15" north, at which time the northern extreme bore east 59º south, nine miles by estimation, an inference which was checked by the distance run on a direct course afterwards. The longitude is 128º 9' east, or 31' east of the observatory.

[Sidenote: Sidmouth Point.]

The coast from the north point runs south-east by east, with some minor deviations, nearly four leagues: great pains were taken to ascertain this precisely, as the former charts not only place it many miles further north, but make the coast at this end lie east and west. The north-east point lies in 26º 47' north, and longitude 128º 18' east, or 40' east of the observatory. The latitude was determined by the meridian altitude of Sirius and an altitude of Polaris, so near daylight that the horizon was well defined; but as this point, off which there is a small island, was some miles north of the ship at the time of observation, the above latitude may err possibly two miles. It was intended to have examined two islands which lie to the north-eastward of the north point, but a strong current in the night carried us so far to leeward, that we could not effect this object; the situation, therefore, of these two islands, may perhaps not be accurately laid down in the chart.

[Sidenote: Barrow's Bay.]

The deep indenture about the middle of the east side of the island is unsafe to enter during the north-east monsoon: as the wind, however, had westing in it, we sailed up to within three or four miles of the top, carrying from thirty to twenty fathoms water; but when about to haul in for the north side, where there appeared to be a bay, we shoaled suddenly from twenty-four to eight fathoms: the helm was instantly put down, and when head to wind, we had only five fathoms. While in stays the water was observed to wash on a rock not a hundred yards to leeward of us, on which we must infallibly have struck, had we bore up instead of tacking.

[Sidenote: South-east coast dangerous.]

From the north-east to the south-east point, the coast runs south 40º west; the shore to the north-east of this deep bight is bold, and seems clear; that on the south-west side of it presents a formidable barrier of islands and coral reefs, which break to a great distance: in fine weather this part of the coast ought to be approached very cautiously.

[Sidenote: South Point.]

[Sidenote: Reef.]

The southern extreme of this island lies in latitude 26º 4' 46" north, determined with great care by the meridian altitude of the sun on shore; and in longitude 127º 35' east, or 3' west of the observatory. There is good anchorage from twenty to thirty fathoms, south a little easterly, of this point. Between this point and the group of islands to the westward, there is a dangerous reef, already spoken of; it lies in 26º 7' north, and 127º 26' east; it bears 26' west, 15º north from the south point of the island, distant eight miles. Immediately round the point on the west side there is a shallow harbour, formed by coral reefs, but the entrance is narrow and intricate.

[Sidenote: South-western group.]

We stood over to the largest of the south-west group, on the east side of which there stands out a conical rock, behind which it was thought that a harbour might lie, but upon examination, it proved only fit for boats; it lies in 26º 11' north.

[Sidenote: Reef Island.]

Reef Island lies west by north, about two leagues from Napakiang Roads; on the north side the reefs stretch a great way, but the south is more clear.

Between Napakiang and the Sugar Loaf there is no place for ships to lie in safety; the bay immediately to the north was examined by Mr. Mayne, master of his Majesty's ship Alceste, when two shallow harbours were found.

[Sidenote: Tides.]

The flood runs to the northward and eastward, along shore, and the ebb in an opposite direction. The rise and fall is about nine feet perpendicular. High water at full and change IX.

[Sidenote: Variation of the compass.]

The variation of the compass, determined with great precision by the transit azimuth instrument, was 52' westerly.

The longitude of the Lyra's observatory at Napakiang by the mean of thirty-six lunar observations on both sides of the moon, is 127º 37' 28" east; by four chronometers, agreeing nearly, 127º 38' 30" east. The latitude is 26º 13' 39" north.

[Transcriber's Note: Crescent moons are denoted by [((] or [))]; a circle with a period therein is denoted by [(.)]]

OBSERVATIONS MADE AT NAPAKIANG OBSERVATORY, GREAT LOO-CHOO ISLAND.

Lunars with a Sextant. Lunars with a Sextant.
[(.)] West of [((] *[Greek: a] Arietis, East of [))]

25th September, 1816. 4th October, 1816

[(.)] [((] 127º. 38'. 15" East. * [))] 127º. 31'. 00" East.
35 . 15 37 . 00
36 . 15 43 . 00
34 . 45 52 . 30
33 . 00 54 . 30
36 . 00 38 . 45
30 . 45 52 . 45
28 . 30 50 . 15
32 . 15 50 . 30
31 . 30 127º. 33'. 39" Mean 41 . 45
40 . 30
26th October, 1816. 34 . 15
43 . 15
[(.)] [((] 127 . 38 . 30 39 . 45
39 . 45 ------------
41 . 30 Mean by sextant 127 . 43. 20 * East of [))]
44 . 15
44 . 30 Lunars by Circle.
32 . 15 [(.)] West of [((]
33 . 00
31 . 45 4th October, 1816
31 . 15 [(.)] [((] 127º. 38'. 45"
27 . 30 127º 36'. 16" Mean 32 . 30
------------- -------------
Mean by sextant 127 . 34 . 58
[(.)] W. [((] Mean 127 . 35 . 37 by circle.

Mean by sextant [(.)] west [))] 127º 34'. 58"
* East [((] 127 . 43 . 20
--------------
Mean longitude by sextant [(.)] * [))] 127 . 39 . 9
by circle [(.)] * [((] 127 . 35 . 37
--------------
Mean longitude by 36 lunars 127 . 37 . 28
Longitude by chronometers 127 . 38 . 30 east of Greenwich.

LATITUDE OF NAPAKIANG.

_By Meridian Altitudes of the Sun and Altitudes taken near Noon._

By meridian altitudes observed. By meridian altitudes deduced in the
usual way from sights taken near noon.

1816. 1816.
Sextant. 8th Oct. mean of 3 A.M.} 26º. 13'. 30" circle.
17th Oct. 26º. 13'. 43" and 3 P.M. }

20th Oct. 26 . 13 . 44 20th Oct. A.M.{ 26 . 13 . 46} sext.
{ 26 . 13 . 44}

Circle.
26th Oct. 26 . 13 . 29 20th Oct. P.M.{ 26 . 13 . 58}
{ 26 . 13 . 47} sext.
{ 26 . 13 . 57}

22d mean 2 A.M.& 2 P.M. 26 . 13 . 24} circle.
26th 3 P.M. 26 . 13 . 29}

Latitude by mean of 3 meridian altitudes 26º. 13'. 39" sextant and circle.
mean of 5 altitudes near noon 26 . 13 . 50 sextant.
mean of 3 do. do. 26 . 13 . 28 circle.
------------
Mean latitude 26 . 13 . 39 north.

* * * * *

VARIATION OF THE COMPASS AT NAPAKIANG.

The declination of the magnetic meridian was ascertained with considerable precision by means of the transit azimuth instrument: the needle seldom showed the same variation, as it oscillated about ten minutes, but the mean position of the magnetic meridian was 52' 10" west of the true. A coral reef was selected for the place of these observations, in order to avoid the attraction arising from buildings, or from inequalities in the ground.

* * * * *

_Variation observed on board by Walker's Azimuth Compass._

29th Sept. 1816, P.M. ship's head W. by S. variation by

1st azimuth 0º. 51'. 30" west.
2nd 0 . 53 . 30
3rd 1 . 17 . 30
Amplitude 1 . 15 . 00
30th A.M. 1st azimuth 0 . 55 . 30
2nd 0 . 34 . 15
3d Oct. A.M. ship's head E.N.E. 1st azimuth 0 . 37 . 00
2nd 0 . 48 . 00
-----------
Variation by mean of 7 azimuths and 1 amplitude 0 . 52 . 39 west.

TABLE OF OBSERVATIONS

MADE WITH

DR. WOLLASTON'S DIP SECTOR:

WITH AN ENGRAVING, AND A DESCRIPTION OF THE INSTRUMENT, AND DIRECTIONS FOR ITS USE.

EXPLANATION OF THE DIP SECTOR,

AND

REMARKS ON THE OBSERVATIONS MADE WITH IT IN HIS MAJESTY'S SLOOP LYRA.

In our tables for apparent dip of the visible horizon at different heights from the sea, as calculated from the known curvature of the earth, allowance is made for the refraction of the atmosphere, on a supposition of its being constant, but as it is known to vary, the tabular dip will often be erroneous, and, consequently, altitudes taken under different states of the atmosphere, will exhibit different instead of corresponding results.

It is foreign to the present purpose to shew what the causes are which have most effect in raising or depressing the apparent horizon. It may be sufficient to mention, that changes in the relative temperature of the air and the sea must produce changes in the refraction near the surface. Dr. Wollaston has published two papers in the Philosophical Transactions on this subject, in the volumes for 1800 and 1803, and to these I beg to refer the reader for precise information upon this very curious subject.

The object which this sector proposes to attain, is the actual admeasurement of the dip angle; that is, to ascertain how much the visible horizon is depressed below the horizontal plane passing through the eye of the observer. The instrument is so contrived as to measure double the dip angle twice over, so that we obtain four times the required dip, and one quarter of this angle is what must be applied to vertical angles, measured from that part of the horizon which has been observed.

Figure I. is the instrument seen in perspective, and Fig. II. is a plan of it with the telescope removed. In order to explain its use, let A and B (Fig. II.) represent the two reflecting glasses at right angles to the plane of the instrument, and also nearly at right angles to each other. It is clear that when the plane of the instrument is held vertically, an eye situated at E, and looking through the unsilvered part of the glass A at a distant point C, will at the same time see by joint reflection from both glasses, another distant point D at 180º from C; and D will appear to correspond with C, if a suitable motion be given to the index glass B by the tangent screw F.

The instrument may now be supposed to measure the arc CZD. If the points C and D be each three minutes farther from the zenith than 90º, the entire angle will then exceed 180º by double that quantity. The relative position of the glasses then corresponds to 180º 6', and the six minutes of excess would be shewn on the arc at F if there were no index error. But, by reason of the index error, the real quantity will not be known till a similar observation has been made with the instrument in an opposite direction.

If the instrument be now inverted, so that the unsilvered glass is uppermost, the arc intended to be measured is CND, or the sum of the distances of the points C and D from the Nadir instead of the Zenith, which of course falls short of 180º by as much as the former arc exceeded that quantity.

The difference of the two arcs is consequently twelve minutes, and if the index be now moved till the objects C and D appear to correspond, the amount of this double difference will be shewn by the _change of position_ of the vernier.

Hence it is evidently unnecessary that the index error should be previously known, and even preferable that its amount should be such as to avoid the needless introduction of negative quantities by positions on different sides of zero.

In the preceding description, it is supposed that the eye is looking directly through the unsilvered glass at the horizon, and that it also perceives the opposite horizon after two reflections; but an inspection of the figure will shew that the observer's head would necessarily intercept the rays from the horizon behind him. To obviate this, both the direct and the reflected rays are received in coming from the unsilvered glass, (and after passing through the field-glass of the telescope) on a mirror placed at an angle of 45º, which reflects them to the eye. By this ingenious contrivance, the obstruction is removed, and the opposite points of the horizon may be both seen at one moment.

In practice, it is most convenient to direct the telescope to the same part of the horizon in both cases. Thus, if the east and west parts of the horizon be observed, and that the index glass be uppermost, and telescope pointing to the west, the observer is on the south side, and his face must be turned to the north. When the instrument is inverted, if the observer turn himself round at the same time, so as to face the south, then the telescope will be pointed as before to the west; but since the index glass is now undermost, the inferior arc will now be measured precisely as if his face were to the north, but with the advantage of the same lights seen in the erect position of the instrument.

In using this instrument at sea for the first time, considerable difficulty arises from the constant change in the plane of the instrument from the perpendicular position, in which it is absolutely necessary that it should be held, in order to obtain a correct observation. What at first appears to be a defect, however, is a real advantage, namely, that whenever it is held in the least degree out of the vertical plane, the two horizons (that seen direct, and the reflected one) cross each other, and it is only when the plane is vertical that the horizons can appear parallel.

The object is to get the two horizons to coincide exactly, and for this purpose it will often be necessary to have them of different shades. This is managed, as in the sextant, by means of the screw, which raises or lowers the telescope. When the telescope is brought nearer to the plane of the instrument, the reflected horizon becomes dark and distinct, but when screwed off it becomes fainter, and is not so well defined. Practice alone can teach the degree of intensity which is most favourable. In general it is best to have one horizon dark, and the other light; then bring them very nearly to coincide, and wait till the ship is steady, at which moment a slight touch of the tangent screw brings them exactly to cover one another. It will happen, of course, that when the coincidence is perfect, there is only one horizon to be seen, and a doubt remains whether all is right, but a slight motion of the instrument, by making the horizons cross each other, defines them at once.

It is advisable to take several observations, and the safest way is to take one first with the index glass uppermost, and then with the instrument inverted, after which to return to the first, and so on for two or three times each way.

In the pages which follow, there is given a table containing the result of all the observations made during this voyage, preceded by several sets of observations in the fullest detail. From the table it will be observed how seldom the dip, actually measured, agrees with that inferred from the mean refraction. Some of these experiments shew very remarkable differences, and point out the great utility of this instrument.