As a knowledge of the origin and course of rivers, conducts in every country to that of the relative altitude and directions of its highlands, the late discoveries on the waters of Africa have thrown great light on its orography.  The sources of the largest, or rather longest of its rivers, namely, the white or true Nile, now appears to be in a point nearly equidistant from the Indian and Atlantic Oceans in one direction, and from the Mediterranean and the Cape of Good Hope on the other.  These central summits, it is fair to suppose, are at least as high as the snowy peak Samen, in Abyssinia, which is the culminating point towards the sources of the minor branch or Blue Nile, and that they are covered, therefore, with perpetual snow.  From hence flow the White Nile, the Djyr, the Bahr Culla, the Congo, and several rivers of the coast of Zanguebar.

As a part of these great African Alps was described to Denham as lying beyond the mountain of Mendefy, the latter would seem to be an advanced northerly summit of them.  The range is probably united to the eastward with the mountains of Abyssinia, and to the westward, terminates abruptly in some lofty peaks on the eastern side of the delta of the Quorra, but not till after it has sent forth a lower prolongation, which crosses the course of the Quorra nearly at right angles, and terminates at the end of 1500 miles, at the sources of the Quorra, Gambia, and Senegal.  A minor counterfort advances from the central range to the northwestward, commencing about the Peak of Mendefy, and vanishing at the end of about 900 miles in the desert of the Tuaricks.  It gives rise to the two Sharys, which flow in opposite directions to the Quorra and the Lake Tchadda, and further north to the streams which flow to the same two recipients from about Kano and Kashna.

Though the knowledge of interior Africa now possessed by the civilized world, is the progressive acquisition of many enterprising men, to all of whom we are profoundly indebted, it cannot be denied that the last great discovery has done more than any other to place the great outline of African geography on a basis of certainty.  When to this is added the consideration that it opens a maritime communication into the centre of the continent, it may be described as the greatest geographical discovery that has been made since that of New Holland.  Thrice during the last thirty years, it has been on the eve of accomplishment; first when Horneman had arrived from Fezzan and Nyffle, secondly when Park had navigated the Quorra as far as Boussa, and lastly when Tuckey, supplied with all possible means For prosecuting researches by water, was unfortunately expedited to The Congo, instead of being sent to explore the mouths of the Niger.

CHAPTER XLIII.