534 SANDS OF EGYPT. 



from the nortlij and it may be said "without exaggeration that the 

 north wind blows for three-quarters of the year.* The effect of 

 winds blowing up the valley is to di-ive the sands of the desert 

 plateau which borders it, in a direction parallel with the axis of 

 the valley, not transversely to it ; and if it ran in a straight Hue, 

 the north wind would carry no desert sand into it. There are, 

 however, both curves and angles in its course, and hence, wher- 

 ever its direction deviates from that of the wind, it might receive 

 sand drifts from the desert plain through which it runs. But, in 

 the course of ages, the winds have in a great measure bared the 

 projecting points of their ancient deposits, and no great accumu- 

 lations remain in situations from which either a north or a south 

 wind would carry them into the valley.f 



The sand let fall in Egypt by the north wind is derived, not 

 from the desert, but from a very different source — the sea. 

 Considerable quantities of sand are thrown up by the Mediter- 

 ranean, at and between the mouths of the Nile, and indeed along 



* In the narrow valley of the Nile, bounded as it is above the Delta by 

 high cliffs, all air-currents from the northern quarter become north winds, 

 though, of course, varying in partial direction, in conformity with the sinu- 

 osities of the valley. Upon the desert plateau they incline westwards, and 

 have already borne into the valley the sands of the eastern banks, and driven 

 those of the western quite out of the Egyptian portion of the Nile basin. 



f These considerations apply, with equal force, to the supposed danger of 

 the obstruction of the Suez Canal by the drifting of the desert sands. The 

 winds across the isthmus are almost uniformly from the north, and they swept 

 it comparatively clean of flying sands long ages since. The traces of the 

 ancient canal between the Red Sea and the Nile are easily followed for a con- 

 siderable distance from Suez. Had the drifts upon the isthmus been as for- 

 midable as some have feared and others have hoped, those traces would have 

 been obliterated, and Lake Timsah and the Bitter Lakes filled up many cen- 

 turies ago. The few particles driven by the rare east and west winds towards 

 the line of the canal, will easily be arrested by plantations or other simple 

 methods, or removed by dredging. The real dangers and diflSculties of this 

 magnificent enterprise — and they have been great — consisted in the nature of 

 the soil to be removed in order to form the line, and especially in the constantly 

 increasing accumulation of sea-sand at the southern terminus by the tides of 

 the Red Sea, and of sand and Nile slime at the northern, by the action of the 

 winds and currents. Both seas are shallow for miles from the shore, and the 

 excavation and maintenance of deep channels, and of capacious harbors with 

 easy and secure entrances, in such localities, is doubtless one of the hardest 

 problems offered to modern engineers for practical solution. See post. Geo- 

 logical Importance of Dunes, note. 



