Science would be much benefited by the careful examination of the names engraved on the maps of Northern Africa, without excepting those recently published, and the indication of the duplicates and false names, which are real blemishes in works otherwise of great value; but this labour, even as regards the countries which belong to my subject, would occupy too much time. The nomenclature is of more importance than is usually ascribed to it by the compilers of maps; I consider it one of the fundamental principles of geography: there are maps which would merit the appellation of classical if they answered in this respect to their precision and merit in all others. Two things are wanting to enable us accurately to fix this nomenclature: the names written by a native, and the pronunciation collected with great attention[111].
§ IV.
OF SOME RESULTS OF THE TRAVELS OF M. CAILLIÉ.
Of all the results, for which we are indebted to the new travels, that which most excites curiosity is unquestionably the knowledge of the city of Timbuctoo; but, perhaps that which is most important to geography is the course of the great central river. Although M. Caillié was unable to give information of it beyond Timbuctoo, he has conferred a real service on science, since he describes its banks with circumstantial detail from Djenné to that city, and gives us an idea of its course above Djenné. By crossing it at Couroussa, and after advancing more than two hundred English miles farther east, then travelling as far as Djenné on the right bank, he has furnished reason for concluding that no river parallel with the Dhioliba exists there, as traced upon the maps. The river, on the contrary, receives in this quarter pretty numerous tributaries, which, from their importance, seem to denote a distant source.[112] We perceive from the description that both banks of the river, a little beyond Bamakou, are very open, and their declivity gentle, which explains the existence of vast accumulations of water, of which the Lake Debo or Dhiebou is the most considerable. Whatever opinion may have been previously formed of the existence of a lake in this part of Africa, we were utterly ignorant of its situation, its true name, its form, and extent. The islets, on which our countryman has thought himself entitled to bestow names, will perhaps one day prove remarkable points. Their occupation would suffice to intercept the navigation upwards and downwards, and by thus rendering their possessor master of the river to influence the commerce of interior Africa; a commerce, comprehending on one hand, the gold extracted from the rich mines of Bouré, and the productions of Kankan, Ouassoulo, and Fouta-Dhialon, the merchandise of the Mandingoes, and all the articles of Djenné; on the other, the productions which Timbuctoo receives from the northern coast, and every thing transported thither by the Moors from the north and north east.
The observation of the river near Djenné affords a still more remarkable modification of received opinions; it must now be acknowledged that Djenné stands on an island, and that this island is double; which, let me remark, by the way, may serve to explain many contradictory accounts both of travellers and natives. The new narrative itself is, I confess, not free from difficulties, I have consequently only traced with dotted lines the branches of the river round Djenné. The following results may, at any rate, be deduced from M. Caillié’s routes by land and water, along the eastern part, and from the intelligence which he obtained respecting the western portion; first, that a large branch diverges near Sego, about forty leagues, (in a direct line), above Djenné; and that it rejoins the main stream at Isaca, twenty-seven leagues below, (forming the first or largest island,. including Djenné); secondly, that near Galia, (or Cou Galia,) is another communication, having itself two branches, and forming a second or smaller island, of which Djenné occupies one extremity; another channel also joins this island with the eastern branch.
This description appears at first sight rather complicated, but its perplexity will be removed if the tracing dotted on the map be admitted. The eastern branch could not have been crossed by Mungo Park, and he knew nothing of it; the same with Dochard. And, as for the second journey of Park, its narrative breaks off abruptly: it is probable that the branch which he followed in the first instance, on which Silla and six other villages beyond Sansanding are situated, is the same branch, which, according to M. Caillié, runs from Sego to Isaca; but Djenné must be carried to the right bank, whereas in the map of Park’s travels it is placed on the left. This circumstance was already learned from Baron Roger[113]; but the new discoveries perfectly explain this contradiction, which is merely apparent; for if Djenné is on the right of the western branch, it is at the same time on the left of the eastern.
This discussion shews that the immense volume of the waters of the Dhioliba is still greater than has been supposed. Park, indeed, who saw only one branch, stood in silent admiration of this majestic stream; but that which M. Caillié crossed before Djenné and followed as far as Isaca is not inferior to the other in importance[114].
The junction of the island with the river, visible from the tops of the houses in Djenné, was pointed out to M. Caillié. Is it with the western arm, or with a branch of the eastern? I am disposed to believe that it is with the latter, the other being at too great a distance to be within sight. I can say nothing positive of the island of Jimbala, and which the maps represent between Lake Dibbi and Cabra, the port of Timbuctoo[115]. There is, however, no reason for doubting its existence, since M. Caillié could not examine all the windings of Lake Debo or Dhiébou, from which an arm may diverge to the right, and rejoin the branch which it runs off to the east near Cabra.
From the travels of M. Caillié we further learn, on the subject of commercial communications, that the navigation of the Dhioliba is almost every where practicable; it is navigable as early as Couroussa, and no doubt yet nearer to its source; there is no reason to suppose any serious obstacle at Bamakou, although there appear to be at this place three principal rapids, but not cataracts. Park navigated it here; the current, by his account (but on the 22d of August, the season when the river is full,) ran at the rate of about five knots an hour. Its bed was a mile in width, and at the point of the rapids twice as much[116].
The observations which I have made above upon the position of Timbuctoo[117] apply equally to the course of the river. Ever since the year 1720, the tracing of this course on the maps has been progressively moving from east to west, drawing nearer and nearer to the Senegambia and to the west coast of Africa. It becomes, also, more and more probable that the mountainous space, which separates these two basons, will be found shorter and more practicable for the passage both of men and animals. Who knows but some large tributary to the Dhioliba may run in the close vicinity of a similar tributary to the Bâfing, or even to the Senegal below Galam, such as the Red River, or the Baoulima, or the Kokoro, so that the communication between these two rivers might be established without much difficulty? Who knows, in short, whether the progress of civilization may not one day effect the construction of a canal between such tributaries, suitable for commercial purposes; and whether we may not then find a navigable communication opened between the mouths of the Gambia and Senegal and Sego, Djenné, Timbuctoo, Houssa, and all the large towns by which the Dhioliba flows?