THE NILE DELTA. 67 



accumulated alluvia are soon swept away and distributed along the coast by the 

 marine currents. In many places these encroachments of the sea have been clearly 

 determined. A distinctly perceptible coast stream sets steadily from Alexandria 

 eastwards to Port Said, here and there developing slight local counter currents, 

 such as the ebb and flow between the Rosetta mouth and Abukir Point. The 

 effect of this stream is to erode the headlands and fill in the intervening inlets, 

 thus restoring the original parabolic curve of the coast. Wherever an obstacle is 

 met, it becomes attached to the mainland by a semicircular strip of sand. Shoals 

 have thus been accumulated at the western pier of Port Said, although not in 

 sufficient quantity to endanger the basins of the new port, especially as they may 

 be easily reduced or removed by dredging. Altogether the annual growth of the 

 delta cannot be estimated at more than 8 or 9 feet, so that since the time of 

 Herodotus the mainland has encroached on the sea probably not much more than 

 3§ miles. 



There may even be a complete equilibrium between the fluvial deposits and 

 the erosions of the marine currents. At least the geological aspect of the coast is 

 that of an ancient seaboard forming a continuation of the small limestone ridge 

 at Alexandria, which at present terminates at Abukir Point. In the shallow 

 waters the waves take advantage of every rocky projection, islet, or headland to 

 deposit sandbanks, and thus gradually transform the irregular marine inlets into 

 landlocked lagoons. Before advancing beyond the mainland the Nile had to fill 

 up these lagoons, separated by strips of sand from the Mediterranean, and this 

 work is not yet accomplished. It would appear to have even been delayed by a 

 o-eneral subsidence of the land, such as has been recorded in Holland, on the coast 

 of North Germany, at the mouth of the Po, in the Amazon estuary, and in so 

 many other alluvial districts. Thus the artificial caves formerly excavated near 

 Alexandria at a certain elevation above sea-level are now submerged. These are 

 the tombs known by the name of " Cleopatra's Baths."* To the same phenomenon 

 should perhaps be attributed the restoration of certain depressions, which after 

 having long remained dry have again been partly flooded. 



But however this be, the lacustrine basins of the delta are now so shallow that 

 they might easily be filled up. The eastern extremity of Lake Menzaleh, which is 

 separated from the Nile basin by the embankments of the Suez Canal, has already 

 become dry land, while the old bed of the Pelusium branch has disappeared. 

 Since Andreossy's survey at the end of the last century, Menzaleh itself has been 

 much reduced, and has now a mean depth of scarcely 40 inches, although covering 

 a superficial area of about 500 square miles during the floods, when it communicates 

 by temporary channels both with the Nile and the sea. At low water it is so 

 beset with shoals and islets that most of the navigation is suspended. 



Lake Burlos, which lies east of the Posetta branch in the northern part of the 

 delta, is scarcely less extensive than Menzaleh, and like it rises and falls with the 

 periodical floods. A sweet- water basin when fed by the Nile, it becomes brackish 

 at other times, and communicates through a single permanent opening with the 



* Sir Ch. Lyell, " Antiquity of Man," 



