5O4 SEDIMENT OF THE NILE. 
The tidal movement of the ocean, deep-sea currents, and the 
agitation of inland waters by the wind, lift up the sands strewn 
over the bottom by diluvial streams or sent down by mountain 
torrents, and throw them up on dry land, or deposit them in 
sheltered bays and nooks of the coast—for the flowing is strong- 
er than the ebbing tide, the affluent than the refluent wave. 
This cause of injury to harbors it is not in man’s power to re- 
sist by any means at present available; but, as we have seen, 
something can be done to prevent the degradation of high 
grounds, and to diminish the quantity of earth which is annu- 
ally abstracted from the mountains, from table-lands, and from 
river-banks, to raise the bottom of the sea. 
This latter cause of harbor obstruction, though an active agent, 
is, nevertheless, in many cases, the less powerful of the two. The 
earth suspended in the lower course of fluviatile currents is lighter 
than sea-sand, river water lighter than sea water, and hence, if a 
land stream enters the sea with a considerable volume, its water 
flows over that of the sea, and bears its slime with it until it lets it 
fall far from shore, or, as is more frequently the case, mingles 
with some marine current and transports its sediment to a re- 
mote point of deposit. The earth borne out of the mouths of 
the Nile is in part carried over the waves which throw up sea- 
sand on the beach, aud deposited in deep water, in part drifted 
by the current, which sweeps east and north along the coasts of 
Egypt and Syria, and lodged in every nook along the shore— 
and among others, to the great detriment of the Suez Canal, in 
the artificial harbor at its northern terminus—and in part borne 
along until it finds a final resting-place in the north-eastern 
angle of the Mediterranean.* Thus the earth loosened by the 
rude Abyssinian ploughshare, and washed down by the rain 
* “The stream carries this mud, etc., at first farther to the east, and only 
lets it fall where the force of the current becomes weakened. This explains 
the continual advance of the land seaward along the Syrian coast, in conse- 
quence of which Tyre and Sidon no longer lie on the shore, but some distance 
inland. That the Nile contributes to this deposit may easily be seen, even by 
the unscientifie observer, from the stained and turbid character of the water 
