Tiii INTRODUCTION 



estimation of the older maps (1614 feet). Still it can- 

 not be much less on the lake levels than fourteen hundred 

 feet; therefore in considering the problems it is not pos- 

 sible to attribute the Kebabo oases, the villages of Kufara 

 to anything more than the site of a largish lake in pre- 

 historic times which sent its waters flowing west into the 

 great Wadi al Fardi, the course of which seems to have 

 passed through Taiserbo to Jaghabub and thence past the 

 oasis of Siwa into the Nile near Cairo. 



The Libyan Desert through which Mrs. Forbes 

 travelled, starting from Cyrenaica and returning to 

 Egypt, is classed by her and by most other persons with 

 the Sahara; which properly speaking lies to the west of 

 a long chain of peaks, ridges, and tablelands grouped in 

 its central section under the name of 'Tibesti', the moun- 

 tainous country of the Tu, Teda, or Tibu (Tebu or Tubu) 

 peoples. But it would almost seem for reason of its 

 past mammalian fauna as though we must distinguish 

 between the Sahara and the Libyan Deserts, just as for 

 similar reasons we do not extend the name of 'Sahara' to 

 cover the sandy and stony wastes of Arabia. The true 

 Libyan Desert — almost a more awful region of desola- 

 tion than the Sahara west of the Tibesti mountains — 

 would seem in ancient human times, fifty thousand, a 

 hundred thousand, two hundred thousand years ago, to 

 have been the western area of the Nile basin. Its mighty 

 rivers, their courses still traceable, fed by the almost 

 Alpine range of Tibesti, by the vanished rain from the 

 plateaus and ridges of Wanyanga and Darfur, flowed 

 towards the Nile between its nascent delta and Kordofan. 

 Its mammalian fauna and to a lesser degree its flora dif- 

 fered in some important particulars from that of the 

 Sahara (then possibly much covered by shallow lakes and 

 inland seas) ; and still more from the beasts and trees of 

 true West Africa or Central Africa. The White 



