Here it is well well worth remarking, that Ptolemy describes a branch springing from the SE, about the parallel of 10°, and amongst the Nubi, which branch flows into the Gir, a river distinct from the Niger, and appearing to answer to the river of Bornou, &c. This accords exactly with Edrisi's idea; only that it does not flow from the same lake as the Nile, separated from it only by a mountain. But M. D'Anville, in my idea, interprets very fairly the scope of the intelligence furnished by Edrisi, by supposing that the sources of the two rivers, or the courses of them, were separated only by a ridge of mountains.* Leo says, that the head of the Niger is within 120 miles of the country of Bornou, and in the Desert of Seu ;† but these notices must be regarded as extremely vague. Certain it is, that if the eastern waters of Nigritia do not run into the Nile, of which, in our idea, there does not appear a shadow of probability, they must either be evaporated in lakes or lost in sands. The lake of Kauga offers itself in a position very convenient for the purpose, and a river taken by Edrisi for the Niger, is actually said to pass near it. It has also been shewn, that in the idea of Edrisi, the Kauga lake communicated with the western waters; but whether this is true, or otherwise, it is not possible to decide. I do not pretend to follow Ptolemy in his description of the rivers in the interior of Africa, with that precision which M. D'Anville has attempted: but this circumstance is clear enough, that he describes them to terminate, as well as to begin, within the continent. The same is to be said of Agathemerus. It is apparent, that Ptolemy has carried the head of the Niger 7 degrees too far to the north and about four or more too far to the west; as also that his inland positions in Africa, as well along the Niger, as at a distance from it, are yet more to the west of the truth. But notwithstanding this Beaufoy; namely, that a branch of the Egyptian Nile, runs into the Desert of Bilma. (Af. As. Q. p. 138; 0. p. 209.) There does not, however, appear to be any foundation for believing that the Nile sends forth any branch above Egypt. All the notices of this kind may, with more probability, be referred to a communication with the waters of Kauga. *Mem. Inscrip- Vol. xxvi. p. 66. geographical error, he proves that he knew many facts relating to the descriptive part of the subject. For instance, he places the source of the Niger at the mountains of Mandrus and among the nation of the Mandori. It has been seen that the Joliba rises in the country adjacent to Manding.He marks also a large adjunct to the Niger from among the Maurali in the south, answering to the river from Malel, or Melli, in Edrisi. To these may be added another particular of agreement. The Caphas mountains of Ptolemy seem meant for those of Kaffaba, a country nine or ten journies to the eastward of Kong; eighteen short of Assenti, or Ashantee, near the coast of Guinea.* But I have a doubt where to place Ptolemy's metropolis of Nigritia, in modern geography. His ideas, however, corroborate in the strongest manner, the present system of geography. Amongst the eastern waters, the Gir of Ptolemy seems to be recognized in the river of Bornou and its adjuncts; the Niger, in that of Tombuctoo and Wangara The Panagra of the same geographer answers to Wangara; and his Libya Palus, which forms the termination of the Niger eastward, seems to be meant either for the largest of the lakes, or for the lakes of that country, of which there are several collectively. In is no impeachment of this opinion, that the Libya Palus is placed so far to the west as the meridian of Carthage, whilst the lakes of Wangara appear to be in that of Cyrene; for Ptolemy carries the river Gir, and the capital of the country which represents Bornou, into the centre of Africa, by which he has shortened the course of the Niger in the same proportion as he had extended that of the Gir, or Wad-al- gazel. Modern geographers to the time of D'Anville, were guilty of the same kind of error. Ghana is about six degrees too far west in Delisle's map. It may be best to omit any further remarks on Ptolemy at present, and to wait the result of future discoveries. in the mean time, those who are curious to read M. D'Anville's Memoir, on the subject of "the rivers in the interior of Africa," will find it in the Mem. Acad. Inscrip. vol. xxvii. CHAPTER VII. Observations on the physical and political geography of North Africa; naturally divisible into three parts; productive in gold. Boundary of the Moors and Negroes ; the Foulahs, the Leucæthiopes of the ancients. To our view, North Africa appears to be composed of three distinct parts or members. The first and smallest, is a fertile region along the Mediterranean, lying opposite to Spain, France, and Italy, commonly distinguished by the name of Barbary; and which, could we suppose the westent bason of the Mediterranean to have once been dry land, (bating a lake, or recipient, for the surrounding rivers,) might be regarded as a part of Europe, as possessing much more of the European than the African character. The second part, is what may be deemed the body of North Africa, comprised between the Red Sea and Cape Verd on the east and west, and having the Great Desert, or Sahara, and its members on the north; the Ethiopic ocean and South Africa on the opposite side. The prominent feature of this immense region, is a vast belt of elevated land of great breadth, often swelling into lofty mountains, and running generally from west to east, about the tenth degree of latitude. Its western extremity seems to be Cape Verd; the mountains of Abyssinia the eastern. Το the north, its ramifications are neither numerous nor extensive, if we except the elevated tract which turns the Nile to the northward beyond Abyssinia. Towards the south, no particulars are known, save that a multitude of rivers, some of them very large, descend from that side, and join the Atlantic and Ethiopic seas, from the Rio Grande on the west, to C. Lopez on the east; proving incontestibly, that by far the greatest proportion of rain-water falls on that side during the periodical season of the SW winds, which corresponds in all its circumstances with the same monsoon in India.* A ridge stretches to the south, through the middle of South Afri ca, and forms an impenetrable barrier between the two coasts. M. Correa de Serra informs me that the Portuguese in Congo and Angola, have never been able to penetrate to the coast of the Indian ocean. Gg To the north of this belt, with the exception of the Egyptian Nile, the waters conform generally to the direction of the high land, passing at no great distance (comparatively) from its base to the right and left; as if the surface of the Sahara had a general dip to the southward. These rivers moreover, receive all their supplies from the south; no streams of any bulk being collected in the Desert. In order to produce this effect, there must necessarily be a vast hollow in the interior of Africa, between the high land of Nubia on the east, and Manding on the west; and of which the mountains and Desert form the other two sides. Nor is this state of things unexampled in the other continents. In Asia, the hollow, to whose waters the Caspian and Aral serve as recipients, is no less extensive than the one just mentioned, reckoning from the sources of the Wolga to those of the Oxus, which latter has ever communicated with the Caspian, either throughout the year, or during a part of it; the difference is, that in Asia a greater portion of the hollow is filled up with water than in Africa. The third part is of course the Great Desert, or Sahara, and its members; consisting of the lesser deserts of Bornou, Bilma, Barca, Sort, &c. This may be considered as an OCEAN OF SAND,† presenting a surface equal in extent to about one half of Europe, and having its gulphs and bays, and also its islands, fertile in groves and pastures, and in many instances containing a great population, subject to order and regular government The great body, or western division of this ocean, comprized between Fezzan and the Atlantic, is no less than 50 caravan journies across from north to south, or from 750 to 800 G. miles, and double that extent in length; without doubt the largest desert in the world. This division contains but a scanty portion of islands (or oases) and those also of small extent; but the eastern division has many, and some of them very large. Fezzan, Gadamis, Taboo, Ghanat Agadez, Augela, Berdoa, are amongst the principal ones; besides which, there are a vast number of small ones. In effect, this is the part of Africa Mr. Bruce learnt (vol. iii. p. 668) that a high chain of mountains from 6 degrees runs south ward through the middle of Africa. He supposes the gold of Sofala to be drawn from these mountains. (p 669.) *Circumstances have shewn that it declines to the eastward also. ↑ "A wild expanse of lifeless sand and sky!” THOMPSON. alluded to by Strabo ;* when he says from Cneius Piso, that Africa may be compared to a leopard's skin. I conceive the reason why the oases are more common here than in the west, is, that the stratum of sand is shallower from its surface to that of the earth which it covers. In other words that the water contained in that earth is nearer to the surfacc, as in most of the oases it springs up spontaneously.t Can any part of the cause be assigned to the prevalent easterly winds, which, by driving the finer particles of sand to the leeward, may have heaped it up to a higher level in Sahara than elsewhere ? The springs, no doubt, have produced the oases themselves by enabling useful vegetables to flourish, and consequently population to be established. That the Desert has a dip towards the east as well as the south, seems to be proved by the course of the Niger also. Moreover, the highest points of North Africa, that is to say, the mountains of Mandinga and Atlas, are situated very far to the west. The Desert for the most part, abounds with salt. But we hear of salt mines only in the part contiguous to Nigritia, from whence salt is drawn for the use of those countries, as well as of the Morish states adjoining; there being no salt in the Negro countries south of the Niger.§ There are salt lakes also in the castern part of the Desert. * Page 130. Water is found at the depth of a few feet in Fezzan (Af. Assoc. Q. p. 96; O. p. 146.) The same is said by Pliny concerning this quarter of Africa, lib. v. c. 5. But farther to the NW. on the edge of the Desert, and in the country of Wadreag, in particular (Shaw. p. 135) wells are dug to an amazing depth, and water mixed with fine sand, springs up suddenly, and sometimes fatally to the workmen. The Doctor tells us that the people call this abyss of sand and water, "the sea below ground" Exactly the same state of things exists in the country round London, where the sand has in several cases nearly fill. ed up the wells. (See Phil. trans. for 1797.) The famous well lately dug by Earl Spencer, at Wimbledon, of more than 560 feet in depth, has several hundred feet of sand in it. Ships that have sailed at a great distance from the African coast, opposite to C. Blanco and C. Bajador, have had their rigging filled with fine sand when the wind blew strong off shore The accumulation of the Bissago shoals may have been partly owing to this cause also. They occupy the position where a great eddy of the general southerly current takes place between C. Verd and Shebro. This quality of the African Desert was familiarly known to Herodotus (Melpom. c. 181, et seq.) He knew. also that there was salt |