Appendix A. 



astronomic studies the city of Alex;iii(lri;i uiid the commercial emporium of 

 Ehapta, lead of themselves to the h3'pothesis that, besides the details gathered 

 from the Greek seafarers along the east coast of Africa, the Alexandrian 

 Geographer also utilized the information obtained in the valley of the great 

 river itself. Nor will this assum])tion appear too bold if we l)ear in mind that 

 long befoi'c the time of Ptoleiiiy, the great Eratosthenes, speaking of the chief 

 branch of the Nile, expi'cssed himself thus : " Two waterways fall into the 

 Nile : they l)oth come from cei-tain lakes lying far to the east and enclosing a 

 very large island known by the name of Meroe. One of these waterways, 

 called Astaboras, forms the east side of the island, the other is called Astapus. 

 Some authors, however, give to the latter the name of Astasobas, and apjDly 

 the name Astapus to another waterway, which they bring from the lakes lying 

 in the region of the south, and legai'd it in some way as the main stream or 

 else as the chief branch of the Nile, adding that its periodical floods are due to 

 the summer rains." ('■') If, as seems beyond doultt, the Astalwras is to ])e 

 identified with the Atbara, the Astasobas with tlie Bahr el-Azrek or Blue Nile, 

 and the Astapus with the White Nile or Bahr el-Abiad (main branch of the 

 Nile), Ptolemy would have l)ut repeated on the whole what three centuries 

 before him had been so well expressed by the Librarian of Alexandria, merely 

 adding on his own \)tivt the positions — latitude and longitude — of the two 

 lakes lying in the region of the south, that is, south of the equinoxial line 

 whose waters feed the chief artery of the all-important fluvial system. 



At this point we meet witli an apjiaiently serious objection. Accoitling to 

 the authors alluded to by Eratosthenes the name Astapus is given to the 

 princi])al bianch of the Nile flowing from the south, whereas Ptolemy applies it 

 to an affluent of the Nile which, issuing from Lake Coloe under the equinoxial 

 line, falls into the main sti'eam at latitude 12° N. But, as above stated, the 

 ol)jection is (jnly apparent. Eiatosthenes, speaking for himself, had already 

 given the nr.xne of Astapus to the river marking the west (and south-west) side 

 of the island (peninsula) of Meroe. that is to say, the Abai or l>ahr el-Azrek. 

 Ptolemy, on his pait, did not think it right to dej)art from the o])inion of his 

 predecessor, and so kept the name of Astapus for the suboi'dinate ri\iM'. It 

 might be iimie inipoitant to notice in the ( ieogi'apliy of the Alexandiian two 

 errors, one of which aflects the Lake Coloe (Lake Tana or Tsana in the heait 

 of AT)VS.sinia), which he places lutdei' the e(|uinoxial line. The other mistake 

 consists in desciibing the .\staboias as a ii\t'i' which mingles its waters with the 

 Asta])Us. r>iu an tMKjnii')' into all these matters, besides lequii'lng too great a 

 ilcvelopment, wduld lie foicign to the (|ncstion of the lakes, sources of the Nile, 

 and to that of the .Mountains of tlie Moon. Notice can only be taken of the 



294 



