BOOK VI. XXXIII. 165-168 



by Ptolemy the Second, who did actually carry a 

 trench 100 ft. broad and 30 ft. deep for a distance 

 of 34i miles, as far as the Bitter Springs. He was 

 deterred from carrying it further by fear of causing 

 a flood, as it was ascertained that the level of the 

 Red Sea is 4i ft. above that of the land of Egypt. 

 Some persons do not adduce this reason for the 

 abandonment of the project, but say that it was 

 due to fear lest making an inlet from the sea would 

 pollute the water of the Xile, which affords to 

 Egj^pt its only supply of drinking-water. Neverthe- 

 less the whole journev from the Egyptian Sca is 

 constantly pcrformed by land, there being three 

 routes : one from Pelusium across the sands, a route 

 on which the only mode of finding the way is to 

 follow a line of reeds fixed in the sand, as the wind 

 causes footprints to be covered up immediately ; 

 another route beginning two miles beyond Mount 

 Casius and after 60 miles rejoining the road from 

 Pelusium — ak)ng this route dwell the Arab tribe of 

 tlie Autaei ; and a third starting from Gerrum, 

 called the Agipsum " route, passing through the same 

 Arab tribe, which is 60 miles shorter but rough and 

 mountainous, as well as devoid of watcring-places. 

 AU these routes lead to Arsinoe,* the city on Caran- -i/ncan coojii 

 dra Bay founded and named after his sister by ° 

 Ptolemy Philadclphus, who first thoroughly explorcd 

 the Cave-dweller country and gave his own name to 

 the rivcr on which Arsinoe stands. Soon after comcs 

 the small town of Aenum — other writers give the 

 name as Philoteriae instcad, — and then there are 

 the Asarri, a wild Arab tribe sprung from inter- 

 marriage with the Cave-dwellers, the islands of 

 Sapirine and Scytala, and then desert stretching 



463 



