66 



NOETH-EAST AFEICA. 



of the marine currents than on the inland floods. But if its height is little 

 modified, its position is often shifted several miles. During the inundations the 

 current of the Nile is felt 3 miles seawards, and at times is strong enough to 

 perceptibly reduce the violence of the waves, thus offering a temporary refuge to 

 storm-tossed vessels. 



The face of the delta is gradually encroaching on the sea, but at a much slower 

 rate than might be expected from the quantity of sedimentary matter brought 



Fig. 23. — Damietta Mouth. 

 Scale 1 : 200,000. 



52° 5' L . of breenwicn 



59'I5- 



to 16 

 Feet. 



16 to 32 

 Feet. 



32 Feet and 

 upwards. 



3 Miles. 



down by the Nile. Even the estimate of 13 or 14 feet annually, as calculated by 

 Elie de Beaumont on a study of the old and mediaeval documents bearing on this 

 point, seems to be excessive, slight though it be when compared with the growth 

 of even smaller deltas, such as those of the Rhine and Po. The charts prepared 

 by the French expedition at the end of the last century, and by M. Larousse in 

 1860, after the completion of the preliminary works for the Suez Canal, give a 

 yearly increase of 130 feet for the E.osetta and 40 for the Damietta mouth. But 

 these are merely local changes, and with the displacement of the channels the 



