Appendix A. 



Hipparchns, Imt which that great astronomer had Iieeii iiiiaMe to realize owing 

 to the great hick of materials. 



The identitj' being thus demonstrated ot Ptolemy's two lakes with Lake 

 Victoria and the Albert-Albert Edward l)asin, we now come to the question 

 of the Mountains of the Moon. That these uplands, lofty enough to feed the 

 reservoirs of the Upper Xile with their snows, are to be placed amiil the 

 Abyssinian highlands, and more particularly in the mountains of Semen ur of 

 Gojam, is a view that must be absolutely rejected. To it aie opp(}sed the 

 northern position of those mountains, the fact that the Abyssinian heights 

 stand altogether outside the upper basin of the White Nile, and perhaps also 

 the altitude itself which, although in some of its peaks rivalling that of 

 Monte Eosa, is still too low to justify Ptolemy's statement, if, indeed, the 

 Geographer intended to speak of perennial snows. 



The Abj'ssinian Mountains l)eing excluded, only two upland groups 

 remain that might aspire to the honour of being identified with the ^lountains 

 of the Moon. These are the Kilimanjaro-Kenia (-'^) and the Kuwenzori groups. 

 There is, however, a serious olijection. Ptolemy (or the Arab interpolation ?) 

 expressly states that the longitudinal axis of those mountains is developed in 

 the equatorial direction along the parallel of 12' 30' S. The Kilimanjaro- 

 Kenia group is, on the contrary, developed in a direction which departs little 

 from the meridian, while that of Euwenzori has a trend nearly from S.S.AV. to 

 X.N.E. Nevertheless, this at first sight most formidable objection may perhaps 

 be overcome, or better, toned down with a consideration of general hydrography. 

 We know that, in accordance with their direction relatively to that of the lines 

 of water-parting, rivers are normally divided into transversal and longitudinal. 

 The first have a trend perpendicular, or nearly so, to the main water-parting 

 line, while the second are jjaiallel, or nearly so, to the same line. To which of 

 these two categories belongs the course of the Upper Nile ? If we regard as a 

 line of water-parting the undulating ground traversing Unyamweziland, and 

 enclosing on the south the Upper Nile Ijasin, and more particularly' that of 

 Lake Victoria, then the U^pper Nile will be classed amongst the transversal 

 rivers. If, on the other hand, we take as main dividing lines either the steep 

 eastern scarp of the great African tableland (the watershed towards the Indian 

 Ocean), or else the series of heights separating Lake All)ert Edward, the 

 Semliki valley, and Lake Albert from the Congo basin, then the Upper Nile 

 will become a lontjitudinal river. Now, bearing in mind the decided trend of 

 the Nile in the meridian direction, it is highly prolialile that we should incline 

 rather to the first than to the second view, and accordingly place the region 

 where the river rises in an u|)laiid tiact lunning perpendicularly to its trend, 



293 



