SANDS OF EGYPT. 535 



almost the whole southern coafit of that sea, and drifted into the 

 interior to distances varying according to the force of the wind 

 and the abundance and quality of the material. The sand so 

 transported contributes to the gradual elevation of the Delta, and 

 of the banks and bed of the river itself. But just in proportion 

 as the bed of the stream is elevated, the height of the water in 

 the annual inundations is increased also, and as the inclination of 

 the channel is diminished, the rapidity of the current is checked, 

 and the deposition of the shme it holds in suspension consequently 

 promoted. Thus the winds and the water, moving in contrary 

 ■directions, join in producing a common effect. 



The sand, blown over the Delta and the cultivated land liigher 

 up the stream during the inundation, is covered or mixed with 

 the fertile earth brought down by the river, and no serious injury 

 is sustained from it. That spread over the same ground after the 

 water has subsided, and during the short period when the soil is 

 not stirred by cultivation or covered by the flood, forms a thin 

 peUicle over the surface as far as it extends, and serves to divide 

 and distinguish the successive layers of slime deposited by the 

 annual inundations. The particles taken up by the wind on the 

 sea-beach are borne onward, by a hopping motion, or rolled along 

 the surface, until they are arrested by the temporary cessation of 

 the wind, by vegetation, or by some other obstruction ; and they 

 may, in process of time, accumulate in large masses, under the lee 

 oi rocky projections, buildings, or other barriers which break the 

 force of the wind. 



In these facts we find an important element in the explanation 

 of the sand drifts, which have half buried the Sphinx and so 

 many other ancient monuments in that part of Egypt. These 

 drifts, as I have said, are not wholly from the desert, but in 

 large proportion from the sea ; and, as might be supposed from 

 the distance they have travelled, they have been long in gather- 

 ing. While Egypt was a great and flourishing kingdom, meas- 

 ures were taken to protect its territory against the encroachment 

 of sand, whether from the desert or from the Mediterranean ; 

 but the foreign conquerors, who destroyed so many of its rehg- 

 ious monuments, did not spare its public works, and the process 

 of physical degradation undoubtedly began as early as the Persian 

 invasion. The urgent necessity, which has compelled all the suo 



