DELTA OF THE NILE. 



163 



the sea once washed the base of the rocks on which 

 the Pyramids of Memphis stand ; the present base 

 of which is washed by the inundation of the Nile, 

 at an elevation of seventy or eighty feet above the 

 Mediterranean. 



The Nile once entered the sea by seven principal 

 mouths, two of which are now entirely blocked up 

 by sand, and have disappeared. The city of Foah, 

 which in the fifteenth century stood on one of 

 these branches, is now more than a mile inland, 

 and Pharos, anciently an island, which Homer says 

 was one day's voyage by sea from Egypt, is now a 

 portion of the continent.* An analysis of the mud 

 of the Nile gives, according to Girard, one half of 

 argillaceous earth, and about one fourth of carbon- 

 ate of lime, nearly one tenth of carbon, the re- 

 mainder consisting of water, silex, oxide of iron, 

 and carbonate of magnesia. At a small distance 

 from the shore of the delta, the depth of the Med- 

 iterranean is about twelve fathoms ; it then gradu- 

 ally increases to fifty, and then suddenly descends 

 to three hundred and eighty*fathoms, which is sup- 

 posed to be nearly the original depth of the sea. 



Deltas of the Ocean. — These are variously modi- 

 fied by the influence of tides and currents, which 

 prevail to a greater or less extent in every ocean, 

 as they often distribute the transported sediment to 

 distant or, perhaps, unknown places of deposite. 



Delta of the Ganges. — The area of this delta is 

 considerably more than double that of the Nile, and 

 its head commences at least 220 miles in a di- 

 rect line from the sea. Its base is 200 miles long, 

 and it is founded on either side by an arm of the 

 Ganges. Near the sea it is intersected by a laby- 

 rinth of rivers and creeks, generally filled with salt 

 water, and forms a wilderness inhabited by tigers 

 and alligators. The Ganges pours such a quantity 



* Odys., book iv., v. 355. 



