Читать книгу Is a Ship Canal Practicable? онлайн

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History for 3300 years bears testimony to the constant movement of the sand, burying all obstructions and obliterating channels which have lain in its path; and the statement of Herodotus, that Lower Egypt is a gift of the Nile, is sustained by a large number of scientific investigators, who maintain that ancient and modern Egypt was reclaimed from an arm of the sea. When nature acts so constantly and irresistibly in one direction, the difficulties of those who contend with her can hardly be overstated.

The winds of Libya, sweeping over the desert, bear the sands irresistibly before them. The ruins of Isamboul and Palmyra are partly buried or threatened by the sand waves. The base of the great Pyramids are concealed, and the gigantic head of Memnon and Sphinx are partially engulfed. The sand dunes near Ismailia move at the rate of ninety-eight feet per annum.

The following excellent description of the sand dunes is taken from Mr. Mitchell’s report: “In the central part of the land of Goshen, where there are broad plains covered with flints, solitary dunes are seen, like golden islands, and they are objects of grace and beauty in every detail. On near approach to one of them, the sands may be seen traveling up the long rear slope before the wind, flying in the air at the crest, and falling down the fore slope in a perpetual cascade—everywhere in motion, but preserving always the same faultless curves. Nor do these dunes leave a grain behind them to mark their tracks. The homogeneous sands of which they are composed are as fine as those usually seen in an hour-glass, and, like the latter, serve to measure the lapse of time in their steady march. The prevailing winds in this part of the desert blow from due north, and are more steady than at Port Said or Suez. In consequence of this, the course of the dunes is so nearly parallel to that of the canal, that their slow approach can always be prepared for. They can at any time be fixed by covering them with brushwood.”