CHAPTER V.

Construction of the New Map of North Africa.*-New Arrangement of the Course of the Nile-Its distant Fountains yet unexplored by Europeans. -A central Position in Africa, determined.-Edrisi's Line of Distance, consistent.-Errors of Leo.

In order that the reader may be enabled to judge of the improved state of the new Map of NORTH AFRICA, I shall set before him a list of the Table of the principal latitudes and longitudes in the Map.

The longitudes thus marked, are from celestial observation, either at the place, or

in the vicinage.

From timekeepers: the two first by Capt. Price, the latter by Capt. Richardson.

authorities, together with an outline of the construction. To enter into a detail of both, would require a volume: I shall therefore barely specify the authorities for the sea coasts, and for such parts of the interior as have been aforetimes described by geographers; and confine the detail to modern discoveries, and to such parts, as those discoveries have helped to improve: and more especially to the points which determine the courses of the Niger and Nile.

The western and southern coasts, from the Strait of Gibraltar to the Equator, have been newly constructed for the present purpose. M. Fleurieu's authorities have been followed in respect to Cape Verd, Cape Blanco, and the Canary Islands. The coasts of Morocco and Fez, rest on the authority of Don Tofino's charts, in the Spanish Atlas: and between Morocco and Cape Blanco, various authorities have been admitted, in the different parts as it appeared to me, that M. Fleurieu had not rightly conceived the position of Cape Bajador.

The coasts on the south and east of Cape Verd, are drawn in conformity to the ideas of Captain Price. This gentleman, in the Royal Charlotte East India ship in 1793, had an opportunity of adjusting the longitudes of some important points: which longitudes Mr. Dalrymple applied to the correction of the existing charts of the coast, and with his accustomed liberality and zeal for the improvement of science, permitted me to avail myself of the use of these corrections, previous to his own publication of them, in a different form. It is to the same invaluable Journal of Captain Price, that I am indebted for some of the most important notices respecting the variation of the compass, along the coast of Guinea, &c.; and without which notices, the approximation of the quantity of variation in the interior of Africa, could not have been accomplished. (See above, page xxvi.)

The result is, that the coast of Guinea has several degrees more of extent from east to west; and that the breadth of South Africa at the Equator, is less, than M. D'Anville had supposed.

No alteration has been made in the coasts within the Mediterranean, save in the form and position of the Gulf of Alexandretta, and the adjacent coasts. The Red Sea, or Arabian Gulf, as well as the whole course of the Nile,

have been re-constructed for the present purpose. For the former, a great collection of new materials has been furnished by Mr. Dalrymple. This includes a new chart of the whole Gulf by Captain White, made in 1795: but I have not followed either that or any other single authority throughout: but have made such alterations as appeared to be warranted, on an examination and comparison of the different materials.

The upper part of the Gulf, between Suez and Yambo, is however preserved entire, as Capt. White drew it.

The position of the Gulf, is thus adjusted:

Capt. White, by two observations of eclipses of Jupiter's first satellite, found the longitude of Suez to be 30° 28' 30" east of Greenwich: and a mean of 76 lunar observations differed less than a minute from the former. The difference of longitude between Suez and Mocha, near the entrance of the Gulf, is, by the mean of five different accounts, 11° 4', which added to 32° 28′ gives 43° 32' for the longitude of Mocha: and which is nearly a mean between the different results, by timekeepers. But until a greater number of celestial observations are taken at the mouth of the Gulf, its position cannot be deemed exact.

Cape Guardafui, is placed by timekeeper observations, in 51° 12′ longitude: 11° 43′ of latitude.

The adjustmenr of the lower part of the course of the Nile, to the shores of the Red Sea, differs very much from M. D'Anville's Map. He supposed that the Nile, in its course from the lower Cataract (near Syene) to Cairo, gradually approached towards the Arabian Gulf: but late observations shew that its runs nearly parallel to it, throughout that extent, which is about 7 degrees of latitude. Hence the distance across, between the port of Kosire and Ghinna, on the Nile, is much less than M. D'Anville supposed; he having allowed about 110 G. miles, although 90 is about the truth.*

It may be proper to state, that the line between Kosire and Ghinna is by no means the shortest, that can be drawn between the Nile and the Red

• Mr. Bruce reckoned 44 hours of the caravan (with camels) between Kosire and Kuft (that is Coptos), near Ghinna: Mr. Irwin 46 from Kosire to Ranute, situated at

Sea, because it runs obliquely between them. The distance appears to be no greater than 72 miles on an ENE course, from Ghinna to the nearest part of the coast.

Cairo, by the mean of several accounts, is about 59 G. miles to the west of Suez, equal to 1° 8' of longitude.* So that Cairo should stand in

the Nile, at five hours above Ghinna. The camel's rate is 2 British miles by the road: consequently less than two G. miles in direct distance.

M. Savary had much the same idea of the distance; for he reckons it 33 French leagues. (Vol. ii. letter 2.) But his Map has 70 G. miles only: Pocock's 90.

Mr. Irwin reckons the bearing WNW from Kosire to Ghinna; doubtless by compass. The variation might be 13 to 14 degrees; whence Ghinna would bear W 9° N from Kosire Banute, which is stated to be about five hours to the south of Ghinna, will therefore by this account bear 1° N of W from Kosire. Mr. Irwin was certainly very near the mark; though a little too much northerly. It appears that Banute is in lat, 25° 47′ 30′′ in D'Anville, and is 8 min. N of Negada; at which place, Mr. Bruce observed the latitude to be 25° 53' 30". Consequently D'Anville is 14 min. too far south in this part. Apply this to Banute, and we have 26° 1' 30". Kosire lies in 26° 8', and Banute is then to the south of it, in reality, by several minutes. At Syene, Mr. Bruce's latitude is 11 min. north of D'Anville's. Not to go into extremes, I have taken Banute at 5 min. S of Kosire, Ghinna 3 min. N of it; or 26° 11'. D'Anville places Ghinna in 26° 1'. It was of much importance that these parallels of the places should be adjusted.

The principal authorities are the following:

M. Niebuhr reckoned between Suez and the Lake of the Pilgrims, situated at 6,9 G. miles E 38 N from Cairo,

M. Volney,

Dr. Pocock,

28h 404

Add from the Lake to Cairo, as it is usually reckoned

mean

2858 3

or say 32 hours 31 58

But as there are (besides the just mentioned 3 hours, in a direction of about 40° from the general line of direction) 34 hours more between Suez and Ajerud, at much the same angle, a considerable reduction of the direct distance must take place, probably about 12 hour whence there remains 30. And as Dr. Shaw states the general report of the distance to be 30 hours, it may be conceived that this is the actual distance, by the shortest route, which leaves the Lake and Ajerud to the north. And for these, 59 G. miles direct may be allowed. M. D'Anville allowed 60.

31° 20'. The Con. de Temps has 31° 29'; but it is probable that Suez is the best determined of the two places.

Mr. Bruce had observations of longitude at Kosire and Syene (or Assuan). The first he gives at 34° 4' and Capt. White at 34° 3'. But as Capt. White gives its latitude at 26° 18', whilst Mr. Bruce found it only 26° 8', we may suppose that the former did not approach the coast near enough to discriminate particulars. Mr. Bruce's parallel intersects the coast in Capt. White's chart, in lon. 34° 8': and I have adopted that for the place of Kosire. Capt. White may perhaps have mistaken the old for new Kosire.

Syene is given at 33° 30' by Mr. Bruce, making 2° 10′ east from Cairo ; whereas M. D'Anville has no more than 41 minutes of easting. Hence arises a difference of 12 degrees in the bearing: M. D'Anville's being about N 9 W; Bruce's N 21 W: or nearly parallel to the shore of the Red Sea.

The longitude of Sennar is 33° 30' 30" according to Mr. Bruce. In this particular is found the widest difference between D'Anville and Bruce; the former placing it no less than 3° 50' more to the west; that is, D'Anville has it, 1° 41' west of Cairo, Bruce 2° 9' east of it.

In effect, then, the general course of the Nile below Sennar lies to the west of north, instead of the contrary, as described in the imperfect materials offered to M. D'Anville. For we cannot doubt the general truth of Mr. Bruce's geographical positions, although we may not be inclined to allow them every point of accuracy. In the observation of longitude at 'Kosire, we have seen that he comes very near to Capt. White: and his longitude of Cairo, is more exact, or more in harmony with Capt. White's observations at Suez, than the longitude recorded in the Con. de Temps. We have moreover another observation of longitude taken by Mr. Bruce at the eastern source of the Nile, 36° 55′ 30′′, (lat. 10° 59′), from whence one route leads eastward to the shore of the Red Sea at Masua, another westward to Sennar. Admitting his observations to be ever so coarsely made, these routes must have afforded so considerable a check, to the distance between Masua and Sennar, as to have precluded any very great error, in a