April 11, 1859.] PIM ON THE ISTHMUS OF SUEZ. 181 



The eastern longitudinal Tains of tlie Libyan Desert, forming the 

 western boundary line of the Nile Valley, is composed of parallel 

 layers of more or less argillaceous and arenaceous limestone, alter- 

 nating with beds of shale of variable thickness, the dryness of the 

 soil imparting hardness to the layers of clay. On the eastern side 

 of the valley, the part we have to do with, the surface consists of 

 loose sand. Sand-hills of some height frequently occnr, and the sand 

 on these hills is so extremely fine that it is put in motion by a very 

 slight wind, and wells 7 or 8 feet deep are filled up in one storm. 

 The highest part of the isthmus is about 40 feet, and is near the 

 Bitter Lake Basin, which is 37 feet below the level of the sea. 

 There are several depressions covered with salt, into one of which 

 (that is to say Lake Timsah) the Nile during inundations some- 

 times finds its way. The basin of Lake Timsah is 2 feet below the 

 level of the Bed Sea. 



To the northward nothing but flat sand- plains present themselves 

 as far as Lake Mensalah, which bears the character of a quicksand, 

 and, consequently, is dangerous to travel near. Below the surface 

 of the isthmus, at a mean depth of 13 feet, water is met with, and 

 most probably the subsoil would partake very much of the " quick" 

 character of Lake Mensalah. 



Such a soil as that just described would be difficult enough to 

 excavate, the sand having a tendency to fall in as fast as thrown 

 out ; and when the watery subsoil is reached, how much greater 

 would be the difficulty ! — in fact it is problematical if a cutting could 

 be made at all. Then, as regards Lake Mensalah, no one can tell 

 to what depth the walls must be sunk before the excavations could 

 be commenced. 



It would seem that when Egypt (780 B.C.) had attained a maritime 

 supremacy, and its commerce began to extend to Arabia and India, 

 the project naturally arose of opening out an easy mode of access to 

 the Nile by means of a canal connecting that river with the Bed Sea. 

 According to Strabo, Pliny, and Aristotle, the attempt to cut a canal 

 to the Bed Sea was first made by Sesostris, about the time of the 

 Trojan war, b.c. 1184. This canal, however, appears to have been 

 intended for irrigating purposes only. Herodotus informs us that 

 the work was commenced in the reign of Nico, b.c. 600, who failed 

 to accomplish his object in consequence of being warned against it 

 by an oracle. The next attempt was made during the Persian 

 occupation by Darius, who is said to have cut from the Bitter Lakes 

 to the sea, but no account can be found of the opening of this canal ; 

 indeed Aristotle asserts that the work was stopped in consequence 

 of the different level of the Bed Sea. 



