vii HAsisAb&A's ADVENTURE 271 



time. Raised beaches, containing recent shells, 

 on the Levantine shores of the Mediterranean and 

 on those of the Ked Sea, testify to a geologically 

 recent change of the sea level to the extent of 250 

 or 300 feet, probably produced by the slow eleva- 

 tion of the land ; and, as I have already remarked, 

 the alluvial plain of the Euphrates and Tigris 

 appears to have been affected in the same way, 

 though seemingly to a less extent. But of violent, 

 or catastrophic^6hange there is no trace. Even 

 the volcanic outbursts have flowed in even sheets 

 over the old land surface ; and the long lines 

 of the horizontal terraces which remain, testify 

 to the geological insignificance of such earthquakes 

 as have taken place. It is, indeed, possible that the 

 original formation of the valley may have been de- 

 termined by the well-known fault, along which the 

 western rocks are relatively depressed and the east- 

 ern elevated. But, whether that fault was effected 

 slowly or quickly, and whenever it came into ex- 

 istence, the excavation of the valley to its present 

 width, no less than the sculpturing of its steep 

 walls and of the innumerable deep ravines which 

 score them down to the very bottom, are indubit- 

 ably due to the operation of rain and streams, 

 during an enormous length of time, without 

 interruption or disturbance of any magnitude. 

 The alluvial deposits which have been mentioned 

 are continued into the lateral ravines, and have 

 more or less filled them. But, since the waters 



