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could be allowed to the cofs in that part; that is, 43 to a degree. But, as we have few meafured lines in the Deccan, I have adhered to the above proportion of 42 coffes to a degree, and have constructed the scale in the map accordingly. And this horizontal cofs, with the allowance of one in feven for the windings of the road, brings the cofs on ordinary roads to one ftatute mile and nine tenths, or 190 miles to 100 coffes.

*

M. D'Anville concludes his enquiry into the length of the cofs, by determining the number in a degree, on a medium, to be 37; but it must be observed, that he had no meafured lines with which he could compare his estimated distances. On the other hand, in the refpective distances of Candahar, Cabul, and Attock, as defcribed by him, each degree contains 47 of Tavernier's coffes.

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SECTION I.

The SEA COASTS and ISLANDS.

ALCUTTA is the point I fhall fet out from, as well from its

CA

being determined by feveral obfervations of longitude and latitude, as from its having a measured line of confiderable extent stretching from it both to the east and weft. I fhall first pursue the route weftward to the mouth of the Indus, and then return to Balafore, and go eastward to the entrance of the ftrait of Malacca.

Calcutta, the capital of the British poffeffions in India, as being. the refidence of the General Council, has its citadel placed in latitude 22° 33′ north; and in longitude, by a medium of the obfervations of four different gentlemen, 88° 28′ east from Greenwich *.

Balafore, fituated about 101 Geographical miles + S. W. from Calcutta, is the most western point determined by the land furvey; but, Capt. Ritchie's marine furvey having been extended to Point Palmiras, and as I confider it as being little inferior, in point of exactness, to the land one, I fhall take Point Palmiras, as if determined by menfuration, from the nearest place of observation, Calcutta. Its latitude is 20° 44', and longitude 87° 2. In the space between Point Palmiras and

6 degrees 33 minutes of longitude

*Hon. Thomas Howe

Rev. Mr. Smith

Mr. Magee
Capt. Ritchie

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- 88. 29

Madras, which contains

‡, no obfervation has

‡, no

Medium

'88° 27′ 45′′

To which may be added the French obfervation at Ghyretty, which is 'eaft from Calcutta

+ I have made ufe of Geographic miles, or thofe of 60 to a degree, in the account of the conftruction of the map; and of British ftatute miles in giving the comparative extent of countries. They are diftinguished by G. miles, and B. miles. Longitude of Madras by the Hon. Thomas Howe's obf. Of Point Palmiras, inferred from Calcutta

Difference

292

80° 29'
87.

6. 33

been

been taken by which the intermediate longitudes may be corrected. However, the direction of the coafts are generally favorable for afcertaining the principal points to fome degree of exactness, by means of the bearing of the compafs and difference of latitude. Accordingly, Capt. Ritchie, in 1770 and 1771, by direction of the Bengal Government, took a series of bearings and diftances, which he corrected by the latitudes, along the whole coaft between Point Palmiras and Madras; an interval of near 600 G. miles. The refult gave 6° 34′ difference of longitude; that is, within 1 minute of the observations; and we may therefore infer that the fituations of Mafulipatam, Vifagapatam, Ganjam, and, in general, all the places along the coaft, differ but little from the truth.

But, as accounts of actual menfuration of fome particular parts of this coaft have fince come to hand, I fhall ftate them in detail, as well for the ufe of future Geographers, as to compare, and, in fome cafes, to corroborate the whole feries.

A line from Mafulipatam to Coringo was measured by Major Stevens, and the difference of longitude in confequence found to

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Here it must be noted, that in this particular place the coaft runs in a direction of 6 points from the meridian; and, confequently, the distance could not be corrected by the obfervations of latitude.

Between Vifagapatam and Jagarnaut Pagoda, an interval of about 180 G. miles, the bearings by compafs, and distance by a Perambulator, were taken by Major Polier in 1759 *, and the refult gave the difference of longitude

By Capt. Ritchie

2° 16′ 30′′

- 2. 18. 00

Not that Major Polier's bearings and distances agree entirely with particular furveys made by others, in places which he paffed

• On his return to Bengal with Col. Ford from the Mafulipatam expedition.

through;

through; for inftance, Lieut. Cridland places Nizambadda and

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24,4 G. miles

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However, it is very certain that Major Polier's measured line by land, and Capt. Ritchie's bearings and distances by fea, differed on the whole only a mile and half in longitude, and half a degree in the angle of bearing. No doubt, if an actual furvey. was taken, we fhould find fome of the intermediate distances too long, and others too fhort, both in Polier's and Ritchie's; but, one error balancing the other, they both come out nearly alike upon the whole.

As the detail of the coaft between Jagarnaut and Vifagapatam is taken from the plans of different perfons, I here fubjoin an account of it:

From Jagarnaut to Ganjam, is from Captain William Campbell: and from Ganjam to Poondy, from Mr. Cotsford.

From Poondy there is a break in the materials for the coaft, till we come to Nowparah; which is fupplied by Major Polier's route from that place to Parfumbah, in Mr. Cotsford's.

From Nowparah to Cicacole, is from Lieut. Cridland; and the remainder to Vifagapatam from Capt. Ritchie.

From Vifagapatam to Yanam, the figure of the coaft is alfo from Capt. Ritchie : from thence to Mafulipatam chiefly from Major Stevens: and from thence to Madras, Capt. Ritchie's entirely.

It

It is proper to remark, that the whole difference of longitude between Calcutta and Madras, in M. D'Anville's and D'Apres' maps, comes within a few miles of the truth, as they were in poffeffion of the obfervations taken at Ghyretty and Pondicherry: but their maps are exceeding faulty in the detail.

The longitude of Madras, or Fort St. George, was afcertained, by the Hon. Mr. Howe's obfervation in 1755, to be 80° 29′, and its latitude taken on fhore is 13° 5'. Pondicherry, by the Connoiffance de Temps is placed in 79° 57'*; and the difference of longitude between them, according to the charts, being 33 minutes, brings the obfervations to agree within a minute of a degree. From Pondicherry to Devicotta, the difference of longitude by the charts, is 6 minutes weft; and, as the whole distance is only about 44 G. miles, and the bearing nearly meridional, no great error can be supposed. This brings the longitude of Devicotta to 79° 51'.

From Devicotta to Tritchinopoly, a measured line was drawn by way of Tanjore by Mr. John Barker, and the difference of longitude found, being 1° 4′ weft, places Tritchinopoly in 78° 47′ longitude. Its latitude is 10° 49'. From thence to Madura was measured by Montrefor, and the difference of longitude given was 20' 30"; by which Madura must be in lon. 78° 26' 30". Laftly, by the surveys taken in the countries of Madura and Tinevelly by order of Col. Call, the difference of longitude between Madura and Cape Comorin is 36' 30", which brings the cape in 77° 50'. Now, as there is nearly a degree of wefterly variation of the needle between Madras and Cape Comorin, it will have the effect of leffening the difference of longitude between them, by at least 3 minutes of a degree; and by that means make the longitude of the cape 77° 53'. And this I take to be the true longitude of it. Its latitude is about 7° 57'.

* M. Gentil's observation in 1769 gave 79° 53', or 4 minutes more wefterly than the Con. de Temps.

5

Until

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