Appendix A. 



Ilippui'clius, l)ul. which that great astronomer had l)een nuulile to realize owing 

 to the great lack of materials. 



The identity being thus demonstrated of Ptolemy's two lakes with. Lake 

 Victoria and the Albert- Albert Edward basin, we now come to the question 

 of the Mountains of the ]\Ioon. That these uplands, lofty enough to feed the 

 reservoirs of the Upper Xile with their snows, are to l)e placed amid the 

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

 Gojam, is a view that must lie al>solutely rejected. To it are opposeil the 

 northei'ii position of those mountains, the fact that the Aliyssinian heights 

 siand altogethei' outside the upjjer basin of the White Xile, and perhaps also 

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

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

 Geograj)her intended to speak of perennial snows. 



The Abyssinian Mountains being excluded, only two upland groups 

 remain that might aspire to the honour of being identified with the Mountains 

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

 There is, however, a. serious objection. I'tolemy (or the Arab interpolation 1) 

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

 the equatoi'ial 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 Kuwenzori has a trend nearly from S.S.W. to 

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

 be overcome, or better, toned down with a consideration of general hydrograph}'. 

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

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

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

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

 these two categories l)elongs the course of the Upper Nile 1 If we regard as a 

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

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

 Lake Victoria, then the U^pper Nile will l)e classed amongst the transversal 

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

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

 Ocean), oi' else the series of heights sepaiating Lake Albert Edward, the 

 Scmliki valley, and Lake Alltert fnmi the Congo basin, then the U])per Nile 

 will l»ecome a longitudinal livei'. Now, liearing in mind the decided trend of 

 the Nile in the meiidian diiection, it is highly probable that we should incline 

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

 where the liver lises in an upland tiact lunning perpendicularly to its trend, 



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