Memoir ... to accompany the New Chart of the Atlantic Ocean, and comprising instructions ... for the navigation of that sea, etc

Front matter

MEMOIR, DESCRIPTIVE AND EXPLANATORY, TO ACCOMPANY THE NEW CHART OF THE ATLANTIC OCEAN, AND COMPRISING INSTRUCTIONS, GENERAL AND PARTICULAR, FOR THE Æatoigattoi* of tfiat ALSO. 1. Tables of the determined Positions of all its principal Points, &c, with the Authorities ; illustrated by Notes. 2. A copious Explanation of the Winds, Tides, Currents, &c; and of the different Passages over the Atlantic, as controlled by these Phænomena : ineluding a General Tide-Table. ?. Descriptions of the Coasts and Islands; particularly of those Parts of the African Coast hitherto imperfectly known, and of the Azores, Madeiras, Cape Verde, and Bermudas', Islands. 4. A Description of Rocks, Shoals, and Vigias; with the Authorities on which they have been inserted in the Chart. COMPILED BY JOHN PURDY. TRUTH DICTATES.

LONDON: PRINTED FOR JAMES WHITTLE AND RICHARD HOLMES LAURIE, CHART-SELLERS TO THE ADMIRALTY, <5*c. 4-c NO. 53, fleet-street. 1812. Cnttrea at S>tationtrs' liMlt. Printed hj Rider and TVbed, Little Britain, London. CONTENTS.

Section I. Remarks

on the CHART, with TABLES of DETERMINED POSITIONS, and the Authorities. page General Remarks 1 1 . England and Wales 3 2. Coasts of Ireland 5 3. France 6 4. Spain and Portugal 8 5. Coasts of Africa 9 6. The Azores or Western Islands 13 7. The Madeira and Canary Islands 14 8. Cape Verde Islands 15 9. Greenland, Labrador, and Newfoundland 16 10. Gulf and River of St. Lawrence, with Cape Breton Island 17 II. Nova Scotia, &c. (Southern Coasts.) 19 12. United States, &c 20 1 3. Bermudas' or Sommers' Islands 21 14. Antillas or West-Indian Islands 22 15. Spanish Provinces, Terra-Firma, &c 26 16. General Note on the preceding Tables. ' 27

Section II. General Observations

on the WINDS, TIDES, CURRENTS, &c, and on the different PASSAGES, over the ATLANTIC OCEAN. 1. Of the Winds and Tornadoes 28 2. Of the Tides 39 3. Of the Currents , 44 Current athwart the English Channel 44 Currents on the Eastern side of the Ocean, between Cape Finisterre and the Coast of Guinea , 48 Currents on the Coast of Guinea. ■ 5.1 CONTENTS. PAGE Current from the Equator to the Caribbean Sea 51 Inset into the Mexican Sea " The Florida or Gulf-Stream, with reflowing Currents off the American Coast "5 Currents towards the Banks of Newfoundland 65 On the general Causes of the Currents, &c 66 4. Ofthe Passages over the Atlantic 68 Of Ships bound to and from the East-Indies 68 Of Ships bound to and from the West-Indies 70 Of Ships bound to North-America, with Observations on the Winds, &c. upon the American Coast 70

Section III. Particular Descriptions

of the COASTS of the ATLANTIC; witfc DIRECTIONS for SAILING among the ISLANDS. 1. England, France, Spain, and Portugal 74 2. Coasts of Africa, with the Isles of St. Thomas, &c 77 3. The Azores or Western Islands 94 4. The Madeiras 104 fi. Canary Islands 107 6. Cape Verde Isles 114 Remarks made on quitting Cape Verde Islands and crossing the Line; By Captain G rant 124 7. Bermudas' or Sommers' Islands 125 8. America and West-Indies 127

Section IV. Description

of the ROCKS, SHOALS, and VIGIAS, and of the Authorities on which they have been inserted in the CHART. 1. Vigias, &c. to the Northward of Latitude 50° 127 2. between Latitude 40° and Latitude 50° 129 3. between 30<> and ~ " — 40* 1 32 4. between 20" and 30* 134 •5. * between the Equator and 20° 134 C. General Note on the Vigias, <_: c 136 ERRATA. Page 3, line 1 1 from bottom : for Rocks read Light-vessel. 10, last line : tor 40' re.-ul __■"■ 15, latitude of Sal: see page 115. 15, third line from bottom : for south-east read south. 16, line 23: for IT read 17". 18, line 7 from bottom: for 9 read 19. 1 6, line 10 from bottom : for Camarines lead Camai bias. 96, line 3 from bottom: for Frio read Pico. EXPLANATORY MEMOIR, &c. THIS WORK IS DIVIDED INTO FOUR SECTIONS, WHICH ARE ARRANGED AS FOLLOW: — 1.

Remarks on the Chart, with Tables of determined Positions, and the Autho. rities. 2. General Observations on the Navigation of the Atlantic Ocean: on Tides, Currents, and the different Passages, outward and homeward. 3. Particular Descriptions of the Coasts of the Atlantic ; particularly thos* which have not heretofore been accurately described: and including Descriptions of •with Directions for sailing among, the Atlantic Islands. 4. Description of the Vigias, or Shoals, in the Atlantic, and of the Authorities on which they have been inserted in the Chart.

Section I. Remarks

on the CHART, with TABLES of DETERMINED POSITIONS, and the AUTHORITIES. THE accompanying Chart, which is, we believe, the only one that exhibits the whole ofthe Atlantic Ocean, upon so large a scale, has been constructed with the particular view of superseding the general use of the Chart on four sheets, distinguished by the name of M. Fleurieu, whose observations regulated many of its important points, but which was realiy constructed by the late M. de la Rochette. and originally published in the house w hence the present work issues, in or about the year 1778. The merits of that Chart have been long and universally admitted ; of which, ex. elusive of a great demand for it, from that time to the present, some degree of proof may arise, from its having been, during this period, more than once carelessly and coarsely copied, and illegally republished, without any attempt at amendment, AVithin the last ten years, however, some defects in it have been ascertained by the observations of various scientific men; and, as the plates have been several times re-engraved, and are now nearly again worn out, it has been deemed more eligible to construct a new one, founded on the present improved state of geography, and agreeable to the most recent observations, than to amend aud repair that draught.

Upon the farmer chart its respected compiler has observed, that, it Is the third of the kind made public. The first having been published some years before at Am sterdam, in four sheets, by Vankeulen, under the title of the Spanish or West^ Indian Sea; it contains some useful details, amidst a thousand errors: the seeondr entitled A Chart of the Atlantic Ocean, was engraven at London, on the circular projection, invented by the late Mr. Murdoch, but was found to be extremely mac* B curate, and the constructor added to the Archipelago of Cape Verde, two islands, under the names of St. Philip and St. John, neither of which existed; these name* being sometimes given by the Portuguese to the Islands Fogo and Brava. M. Rochette adds, that, in composing his chart, he had many helps for the detail of the Coasts; and they have been laid down from a great variety of terrestrial and marine admeasurements, corrected by the best astronomic observations.

Our object here is not to give a history of charts ; we shall therefore only add to these remarks, that, the determinations before made use of, which have been con firmed, have been strictly adhered to; and later observations have been carefully compared with those whichhave preceded them. The result of a general comparison has been, that many positions, rejected by the editors of the most authentic Tables of Positions have been retained, while others, though subsequently given, have been merely taken into comparison; and a few, from their discordance, altogether re jected. It is to the extended practice of lunar observations, and the use of chronometers, since the year 1768, that we owe our great improvements in Modern Geography. It cannot, however, be expected that all who practise these methods are equally skilful and experienced; or that, even if skilful and experienced, they can possess instru ments equally correct.

The most excellent observer, with an imperfect instrument, and the most imperfect observer with an excellent instrument, obtain results equally erroneous. But such truths, with their consequences, are so obvious, that we hasten to the detail of authorities on which the chart is grounded. To the Grand Trigonometrical Survey of England and Wales are owing the cor rect positiou of all the points in the Southern and South-western parts of the kingdom ; and to that of France are, in Tike manner, owing tl>e equally correct positions of all the points of that country.* The Coasts of Spain and. Portugal have been laid down in accordance with the valuable surveys and determinations of the accurate and celebrated Tofino ; and, in the delineation of the A fiucan Coasts, we have followed the positions afforded by Messrs. Fleurieu, Verdun d* la Crenne, Borda, and Pingre', of France, by Sir George Young, aud several other intelligent officers, of our own country.

The American Coasts are exhibited according to the observations and surveys of Cur illustrious countryman Captain James Cook, those of Lieut. Michael Lane, the Surveys of M. de Barres and of Captain Holland, the New Maps of Upper and ■Lower Canada, corrected by astronomic observations ; the observations of M, Chabert, of Messrs. Wright, Mason, Dixon, and Rittenhouse; of Captain Penrose, Lord Cochr ane, and Mr. Downie, &c. &c. The accurate position of the Bermudas owes its origin to Thomas Hurd, Esq. Captain in the Royal Navy, &c, by whom these islands were surveyed under the orders of the Lords Commissioners of the Admiralty. For the correct delineation of the West-India Islands, much has been derived from the labours of Messrs. Puysegur, Verdun, Borda, Pingre', and other foreign * The results ofthe English Survey will be generally considered as final determinations ; as the results of the French Survey have already been ; it is," therefore, to be regretted that a few inac curacies have been discovered in the volumes relative thereto.

We notice this particular, because it appears, from the New Map of Devon, to be the intention, iu future, to omit the meridians and parallels, with the graduations of latitude and longitude, ou the Maps. There will, consequently, be no immediate mean of detecting any of those little errors which will unavoidably occur in the reports ofthe progress of so great and elaborate a work. We confess, with much reluctance, that this omission of graduation, and of reducing the maps to the usual projection, appears to us like the sacrifice of a great principle to a Iittl_ one; it is an omission that may accommodate the District Surveyor; but, weare persuaded that, the Geographer, the Nauigalor, and the World in general, will consider it rather as a defect than as an improvement. This objection is stated in sufficient time to be obviated : but, at all events, the work will remain a durable monument tot the honour of those by whom it has been conducted, and an honour to the country in which it baa been produced.' The national character is interested ia it; and our wilh is to see it perfetl. eflicers, whose observations and results have been subsequently corrected, by the skilful observers, acting under the orders of the Hydrographic Directors of Madrid ; to whom, and to Messrs. Humboldt, Olimanns, &c, we are indebted for the nu merous and accurate determinations of all the points of the Spanish Territories in America.

Jamaica is exhibited according to the surveys and numerous observations of the ingenious Mr. John Leard, of the British Navy, and the details of the other islands according to the best topographic surveys and particular charts. We may truely add, lastly, in the language of a preceding work, that every source has been exhausted to obtain means for rendering this chart as exact as the present state of geography will permit; we, therefore, now proceed to give a detailed account of each determined point, to mention the authorities, and name the observers; in short, to report all that can inspire the navigator with the confidence "which we think due to this work. This is done in honour to those who have made the observations ; to encourage others to imitate them ; and to establish the con fidence of navigators in those parts of the chart for which we have had sufficient ma terials, or to caution them against those which are not yet accurately known.

The Tables which follow exhibit the Positions of Points assumed in the construe. tion ofthe Draught, illustrated by notes. They will be found highly useful in furnish ing the mariner, satisfactorily, with his required course and distance, to a precision unattainable by the mere use of any General Chart ; and will, also, be found a useful accompanyment to every particular Chart of the Coasts of the Atlantic extant. 1. ENGLAND and WALES. The Figures in parentheses refer to the Notes subjoined to each Section. Latitude, i Longitude. Latitude. Authorities. GREENWICH, Royal Observatory- London, Cupola of St. Paul's Church Gravesend, Church Sheerness, Flag-staff Orford High Light-house North Foreland, Light-house South Foreland, High Light-house Dover Castle (The Keep) Folkstone, Church Dungeness Light-house Beachy Head (Station in the Survey) Brighthelmstone, Church Shoreham Church » — Selsey Church Chichester Spire Sea-Ower Rocks Portsmouth Academy South-Sea Castle Calshot Castle Hurst Castle Dunnose (Station in the Survey) St. Catharine's Tower, Isle of Wight Needles Light-house Christchurch Head Poole Church Portland Upper Light-house " I II ° / " 51 28 40|0 0 0* 51 30 49 0 5 47 W. 51 27 39 0 22 10 E. 51 26 45 0 44 2G E. 52 5 0 1 34 14 E. 51 22 25 1 26 34 E. 51 3 261 22 6 E. 51 7 47 il 19 7 E. 51 4 47 1 10 52 E. 50 55 10 57 48 E. 50 44 24 0 15 12 E. 50 49 32 0 7 40 W. 50 50 0 0 16 19 W. 50 45 19 0 45 41 — 50 50 11 0 46 36 — 50 39 57 0 39 59 — 50 48 2 1 6 1 — 50 46 43 1 5 2 — 50 48 13 1 18 6 — 50 42 23 1 32 46 — 50 37 . 7 1 11 36 — 50 35 33 1 17 51 — 50 39 53 1 33 55 — 50 42 57 1 45 11 — 50 42 50 1 58 55 — 50 31 22 2 26 50 — The Astronomers Royal.

The Grand Trigonometrical Survey of England and Wales, commenced in the year 1784, by the late General Roy, F.R.S. under the direction of the Royal Society; subsequently, under the orders ofthe Duke of Richmond, Master General of the Ordnance, and now proceeding under the direction of Lieut. Col. Wm. Mudge, of the Royal Artillery, F.R.S. &c. These operations, carried on in the most masterly and scientific manner, determine, with the similartriangles of France, hereafter noticed, the relative positions of all the points in the English Channel, &c. ENGLAND j WALES CONTINUED. AND NOTES. 1. St. Nicolas or Drake's Island. Mr. Bayly, from his observations made in the observatory of Drake's Island, in 1772, concluded its latitude to be 50° 21' 28"; and the longitude, by means ofthe occultation of a star by the moon, compared with correspondent observations made at Greenwich, as 4° 13' 30".

See " Observations made during the second and third Voyages of Captain Cook," by order ofthe Admir dty. 2. Lizard Point. Dr. James Bradley, Astronomer Royal, from the mean between the re sults of several observations of the satellites of Jupiter, the passage of Venus over the sun in June 1769, and an eclipse ofthe sun on the 4th of June, in the same year, deduced the latitude of the Lizard Point as 49" 57' 30", and its longitude 5° 13' 0". This is tbe position given at present in the general table contained in the Requisite Tables. 3. St. Agnes' Light-house, Scilly. The observations made for determining the situation of St. Agnes' Light-house, at the commencement of the third voyage of Captain Cook, prove to be incorrect. It appeared, from these observations, to be in latitude 49° 55', longitude 6" 45'.

This error, of more than 25 minutes of longitude, has been very injurious, inasmuch as many charts have been subsequently regulated by the deduction. For, the Lizard Point having been previously determined by Dr. Bradley, these islands have, in consequence, been placed much tod far from the Land's End. The fluctuation has, however, been completely set at rest Latitude. Longitude, Authorities. o / u o I '/ Lyme Cobb Berry Head, Flag-staff Start Point, Flag-staff Bolt-Head ' Eddysrone Light-house • Mewstone, near Plymouth Sound St. Nicholas' or Drake's Island, Plymouth Sound [1] - Penlee Beacon Rame Head Dodman or Deadman Point, Flag-staff. St. Anthony's Head, Flag-staff Pendennis Castle, Flag staff St. Kivern's Steeple Blackhead, Flag-staff Lizard Upper Light house [2 ] St. Pau''s Steeple, Mount's Bay St.Leven's Point, Flag-staff Land's End Stone Scilly Islands — St. Agnes' Lighthouse [3 ] i St. Martin's Day- 50 43 10 50 24 1 50 13 26 50 13 14 50 10 55 50 18 30 2 55 29W. 3 28 14 — 3 38 21 — 3 48 0 — 4 15 3- 4 5 33 — 50 21 21 50 19 24 50 13 52 50 13 20 50 8 34 50 8 49 50 3 6 50 1 12 •19 57 44 50 1 24 50 3 54 50 4 7 4 8 18- 4 10 40 — 4 12 29 — 4 47 4 — 4 59 31 — 5 1 44 — 5 4 8 — 5 3 59 — 5 11 5- 5 21 43 — 5 41 4 — 5 41 32 — .

The Grand Trigonometrical Survey of England, &c. 49 53 37 6 19 23 — mark St. Agnes' Beacon, Cornwall Trevose Head Hartland Point , Lundy Island, St. Anne's Chapel -Bridgewater Spire - Bristol Cathedral Worms Head St. Anne's High Light-house, entrance of Milford Haven Small's Light-House [4.] Grasholm Ramsey Isle, (Highest Point) St. David's Cathedral Northern Rock ofthe Bishop and Clerks 49 58 3 50 13 27 50 32 57 51 1 22 51 9 57 51 7 41 51 27 6 51 33 56 6 14 39 — 5 11 56 — 5 0 54- 4 30 26 — 4 38 28 — 2 59 39 — 2 35 29 — 4 18 56 — 51 40 59 51 43 18 51 43 55 51 51 43 51 52 56 51 54 10 5 9 10- 5 38 54 — 5 27 32 — 5 19 36 — 5 14 53 — 5 21 58 — oy the Trigonometrical Survey and the observations of Joseph Huddart, Esq., F. R. S., &c. This gentleman, a few years since, visited the Sclly Isles, having with him a watch made by Arvol-I, and obtained bis lime at that spot where the body of Sir Cloudesley Shovel is said to have been tin own ashore, by means of equal altitudes of the sun's limb : he then found, com paring his time with thai shown by the watch, that ©h. 25m. 18s. was the difference in timo between the meridian of Greenwich and this spot in St. Mary's. Now, St. Agnes' Light-house is about 2min. of a degree West of the place to which Captain Huddart alludes; therefore, 25' 18" -f 8" = 25' 26", is the longitude of St. Agnes by these means; which differs only 4^ sec.

In tmie, or little more than one minute of longitude, from that found by the survey.— Trig. Surv. Vol. II. p. 135. 4. Smalm and Grasholm. In the third Volume of the Account of the Trigonometrical Survey, the longitude of Grasliobn is stated to be 5° 47' 1", and that of the Small's Light house is printed 5" 58' 34"; but they sjre stated as in the table from a re-computation, communicated by Mr. J. Outhctt. 2. COASTS IRELAND OF NOTES. 1. Dublin. The late Rev. Dr. Ussher, an excellent astronomer, F.R.S., and Professor of Astronomy in the university of Dublin, deduced, from tbe result of numerous observations, the latitude of his observatory, in Mecklenburg Street, 53° 21' 2", and its longitude, 25 mi nutes of time, or 6"1 15' VV. from Greenwich. In tbe last edition of the Requisite Tables, the position of Dublin is, however, given as 53° 22' 0", and longitude 6* 17' 0".

If we assume tbe longitude ofthe coasts of Wales, according to tbe Trigonometrical Survey, and add to this the longitude thence to Dublin, according to the esteemed Chart by Captain Huddart, it will appear that the position given in the Requisite Tables is confirmed. The French Tables, entitled tbe Connuissance des Terns of 1803-4, have given the position of Dublin as 53° 21' 11", and 6" 16' 15"; and, in later editions, the same latitude, with lon gitude 6C 19' 0". The position above assigned appears, therefore, to be sufficiently exact for all practical purposes. 2. Cork. The position of Cork has been determined by good observation* made by Dr. Longfield, originally communicated in the Philosophical Transactions of 1771, and again no ticed by Dr. Beaufort, in his valuable "Memoir" relative to a Map of Ireland, 1792. 3.

Cape Clear. The position of Cape Clear does not yet appear to be satisfactorily ascertained. Mackenzie, in bis survey, placed it in lat. 51° 19'; which has, subsequently, been generally adopted. According, however, to observations actually made on this point by Admiral Knight, when captain of his Majesty's ship Montague, it lies in latitude 51° 25", longitude 9° 30'. But the longitude, as deduced per Maps, by Dr. Beaufort, from that of Dublin, is 9° 24'; which we conclude, on comparison with other remarks, to be nearer to the truth, and have consequently adopted. It appears to be well ascertained, that the S.W. Coasts of Ireland have been laid down in the surveys of Mackenzie, &c, too far to the south. By a paper, printed for the Hydrographic Office at the Admiralty, in 1801, entitled, "Remarks on the S.W. and N.W. Coasts of Ireland," by Lieut. T.G. Shortlund, of H.M.S. Melpomene, it appears, that, on making Dursey Island, off Bantry Bay, this gentleman observed with one of Ramsden's best sextants, -and found the latitude ofthe S.W. end of it 51" 37" North; and, being off there for three sue Latitude.

LongiludeWi AUTHORITIES. o I II o ' II City of Dublin [1.] Wicklow Pier City of Cork [2.] Cape Clear [3.] Galway [4.] Tory Island, N.W. point 53 21 30 52 59 0 51 53 54 51 22 30 53 16 0 55 17 45 6 17 0 8 30 0 9 24 0 Requisite Tables, &c. Dr.Ussher.Capt. Huddart,&c-. Dr. Longfield. ■ Mean Results. A pupil of Dr. Ussher. Deduced. 8 12 REiMARKS ON THE CHART cessive days, still found it the same; every quadrant in the ship, at the time, agreeing withlji a mile or two of his observation. Sailing still on, past the Skelligs and Blasquets, next day, he observed off the mouth ofthe Shannon, and found, according to his instruments, Loop Head to be in 52" 37'; Kerry Head 52° SO1; and Brandon Head 52° 22'. Lieut. Shortland remarks, that he was off there five days, and had excellent observations. From the Shannon, he adds, they bad no opportunity of seeing the land, until off Urris Head, whose latitude he made to be 54° 28'; and it was in ferred, that the parts of the coasts of Ireland, between Dursey Island and Urris Head, had been laid down from 10' to 12' to the southward of the truth.

"Tbe danger of which is, that, should a ship be running for the Shannon, and get a good observation, and run in the parallel of 52° 24', or 52° 26', and afterwards have thick weather, she would, instead of making the entrance of the Shannon, or Loop Head, run into Brandon or Tralee Bay; and, should it blow bard from the W.N.W., or West, so that she could not weather round Kerry Head, the consequence would be dreadful, from the heavy sea and foul ground in both these places. " The same would hold good in running either for Bantry Bay, or any other place on the S.W. and West coast." It appears that, from circumstances precisely as here described, the York, Indiaman, was lost in Tralee Bay, 29th October, 1753. To these remarks are added, by Mr. Dalrymple, late Hydrographer to the Admiralty: " Cape Telling, the northern point of Donegal Bay, is rightly laid down ; but Urris Head, the southern point, is 10 min. to the southward of the truth, therefore Donegal Buy is not so zoide, by 10 miles, as the Charts lay it down."

As the paper here referred to has already, without examination or comment, been inserted verbatim in some books of Sailing Directions, and as, from tbe authority under which it appears, it may probably tend to create some errors in Charts equally as great as those which it is calculated to expose; it may be proper to notice that, having referred to the best documents upon the subject, we cannot, by any means, admit that error or difference to exist winch is stated in the latter part of it, in regard to Donegal Bay, &c, although we admit a correction to the southward ; and, surely, before pronouncing the sentence of extermination on so large a portion as 10 miles of his Majesty's kingdom of Ireland, farther enquiry ought to have been made as to the effect ofthe given remarks upon the land to the eastward.

Those who have perused the curious note on the refraction of the atmosphere, in the Account ofthe Grand Trigonometrical Survey, vol.2, p. 132, will readily admit that we cannot pretend to make a positive determination, by celestial observations, taken at sea, correct to a minute ; unless by numerous and repeated observations, made in different states of the atmosphere. From such considerations we are inclined to think that Loop Head does not lie quite so far to the North as placed by Lieut. Shortland. Truth is commonly to be found in a mean between ex tremes; and, probably, if we commence with Cape Clear, in 51° 22' 30", which we believe to be very nearly its true latitude, and thus proceed with the correction, saying, Dursey Island, S.W. end, 51° 37'; FozeRock52« 5'; Kerry Head 52« 27|'; and Loop Head 52° 35', we shall not be far from the truth.

A small Map of Ireland, thus regulated, without any contortion ofthe land, may be seen in a little work lately published, entitled " Laurie and Whittle's Juvenile Atlas." 4. Galway, Tory Island, &c. The latitude of Galway is the result of repeated solar and a few lunar observations. The latitude of Tory Island is that assigned by Captain Huddart; but we cannot find that any positive determination of longitude, by observation, has been made od this or any other of the northern points of Ireland. It may here be sufficient to add that, for the Western Coasts of Scotland, we have made use of the Survey by Captain Huddart ; a chart exhibiting the data on which it has been con structed; for St. George's Channel, &c, the Survey, also, of the same gentleman; and, for the North Sea, the New Chart of Laurie and Whittle, delineated by the compiler of the present ■work. 3.

FRANCE. NOTES. 1. Paris. The grand operations, in point ofaccuracy, for the determination of the length of the degrees of the meridian, have taken place since 1783. In that year a memorial was transmitted by M. Cassini de Thury to the Right Hon. Charles James Tox, then Secretary of State, shewing the advantages that Astronomy would derive from the construction of a series of triangles, that should connect, trigonometrically, the observatories of Greenwich and Paris, and thus correctly determine their relative positions. This application caused tbe operations by General Roy, already explained, which have since extended into a General Survey. This gentleman, in England, acted in conjunction with Messrs. Cassini, Mechain, and Legendre, in France; but, it unfortunately happens that, the results ofthe two parties do not exactly agree.

That of the British officers being, for the difference of longitude, 2° 19' 51", while that of tbe French is 2° 20* 15". We have therefor© stated it, after Dr. Maskelyne, as 2° 2C; and have assumed this as the difference ofthe meridians, whenever we have given the longitudes from French observations. 2. Antwerp. Mr. Pinkerton, in the first page of his " Memoir on the State of Geo graphy," observes, " It is said that, in successive editions of the Necessary Tablet, Anvers was put under one latitude and longitude, and Antwerp under another." The Table referred to, (in the Requisite Tables,) exhibited a difference in longitude only, and that a small one, which has been altered in the last or third edition. It is rather singular tbat this identical error should exist in the table in Mr. Pinkerton's own Book; where, also, Genoa and Genes are stated as two places in different longitudes.

The position of Antwerp, as given in the Table above, is that recently furnished by the French observers. 3. General Note. Some emendations from re-computation have been lately made. Our positions nre therefore given -according to the Connaissance del Terns for 1811. Latitude. -1 I II Longitude. o I II Authorities. PARIS. (Imperial Observatory) [l.] • • Antwerp (Auvers) [2.] Flushing (Flessingue) on Walcheren- ■ Ostende Nieuport Dunkirk (Dunkerque) Calais • Boulogne Dieppe Le Havre Cape la Heve (Light-house) Cape Barfleur (Light-house) Cherbourg Cape Frehel (Light-house) Ushant (Uuessunt) Light-house Brest (At the Prefecture) L'Orient Belle Isle (Pt. Locmaria) Noiimoutier I. Nantes Isled' Veu(W.Pt.) Rhe or Re Island Light-house Oleron (Tour de Chassiron, Light.)

La Roclielle Rochefort- • > Cordouan Light-house Bordeaux Bayonne 48 50 14 51 13 22 51 26 37 51 13 57 51 7 54 51 2 10 50 57 32 50 43 33 49 55 34 49 29 14 49 30 42 49 41 45 49 38 31 48 41 10 48 28 8 18 22 43 47 45 11 47 17 17 47 0 5 47 13 6 46 42 26 46 14 49 46 2 51 46 9 33 45 56 10 45 35 14 44 50 14 43 29 15 2 20 0 E. 4 24 4- 1 14 15 — 2 54 53 — 2 45 0- 2 22 23 — 1 51 1 — 1 36 33 — 1 4 29 — 0 6 23 — 0 3 59 — 1 16 30 W. 1 37 18 — 2 19 2 — 5 3 21 — 4 29 0- 3 21 17 — 3 5 0 — 2 14 22 — 1 32 59 — 2 19 50 — 1 33 40 — 1 24 27 — 19 2 — 0 57 49 — 1 10 10 — 0 34 14 — 1 28 41 — From the triangles intended, originally, merely for the admeasurementof the degrees of the meridian in France, but ultimately carried on throughout the kingdom; These were commenced by M. Picard, who effected an admeasurement between Paris and Amiens in 1699, and finally completed by Messrs. Mechlin and Delambre, in 1798; after having exercised the abilities and industry of M. Cassini the elder, his son, and grandson; of M.M. Maraldi and De Ia Caille, with other of the most eminent French Astronomers, &c. 4.