CHAPTER V.
Construction of the New Map of North Africa.[91] — 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 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 of 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 Capt. 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.