On the Arabian Frontier of Egypt. 27 



the Red Sea ; while the rocky plateau capped with sand-hills 

 rises suddenly on both sides from 30 to 50 feet above it, shews 

 us that, before the first centi'al shoal in the strait that once 

 separated Egypt from Arabia had risen to the water's edge, 

 and parted the Mediterranean from the Red Sea the whole 

 valley formed another narrow strait nearly at right angles to 

 the first, so that the hilly tract north of the valley was a 

 large island. 



The sediment of the Kile being drifted into it, as in other 

 contiguous parts of the sea, while the whole of the present 

 Delta was yet under w^ater, this part of the strait ■would end 

 in having a smooth ground corresponding in level to the other 

 parts of the Delta. So that afterwards, when the seas were 

 divided by the rising of the central shoal,* and the waters 

 of the Mediterranean began to evaporate, and the Nile be- 

 gan to send out arms towards the retiring sea in all pos- 

 sible directions, one of these arms might well make its way 

 along the low ground of this valley, till it reached the point 

 where the bottom of the strait had been originally higher 

 than the Delta, which is near Hero. But over this natural 

 obstacle, the water could not pass, at that remote epoch, 

 when the Nile was law. For, as the soil at the apex of the 

 Delta was then considerably lower than it is now, so the level 

 of the water-line was proportionally lower. It was only during 

 the inundation season that the river could attain a sufficient 

 height to form a superficial cuiTent over this acclivity, so as 

 to run into the basin of the Crocodile lakes, — and out of these 

 again along tlie low marshy tract left by the retiring northern 

 sea. 



One consequence of this formation is, that the annual de- 

 posits of the Nile must, for a considerable part of the year, 

 have been accumulated exclusively in the western half of the 

 valley, known as Wady Toomilat. Indeed, at a remoter pe- 

 riod than that represented by the map, this may have formed 

 a long shallow lake, with a river flowing part of the year 

 into it, and the other part through it. We cannot conclude 

 any thing positive on this state of things, from tlie mere fact, 



* At the spot marked I'i-ha-hirotli in thu map. 



