454 SAND CARRIED DOWN TO THE SEA. 
rivers of the Netherlands u move sand only hy a very slow dis¬ 
placement of sandbanks, and do not carry it with them as a 
suspended or floating material.” The sands of the German 
Ocean he holds to be a product of the “ great North German 
drift,” deposited where they now lie before the commencement 
of the present geological period, and he maintains similar 
opinions with regard to the sands thrown up by the Mediter¬ 
ranean at the mouths of the Nile and on the Barbary coast.* 
Sand now carried to the Sea. 
There are, however, cases where mountain streams still 
bear to the sea perhaps relatively small, but certainly abso¬ 
lutely large, amounts of disintegrated rock.f The quantity of 
observed by Andresen on the shores of Jutland. Laval estimates the total 
quantity of sand annually thrown up on the coast of Gascony at 6,000,000 
cubic metres, or more than 7,800,000 cubic yards. 
* De Bodem van Nederland , i, p. 339. 
t The conditions favorable to the production of sand from disintegrated 
rock, by causes now in action, are perhaps nowhere more perfectly realized 
than in the Sinaitic Peninsula. The mountains are steep and lofty, unpro¬ 
tected by vegetation or even by a coating of earth, and the rocks which 
compose them are in a shattered and fragmentary condition. They are 
furrowed by deep and precipitous ravines, with beds sufficiently inclined 
for the rapid flow of water, and generally without basins in which the 
larger blocks of stone rolled by the torrents can be dropped and left in 
repose ; there are severe frosts and much snow on the higher summits and 
ridges, and the winter rains are abundant and heavy. The mountains are 
principally of igneous formation, but many of the less elevated peaks are 
capped with sandstone, and on the eastern slope of the peninsula you may 
sometimes see, at a single glance, several lofty pyramids of granite, sepa¬ 
rated by considerable intervals, and all surmounted by horizontally strat¬ 
ified deposits of sandstone often only a few yards square, which correspond 
to each other in height, are evidently contemporaneous in origin, and were 
once connected in continuous beds. The degradation of the rock on which 
this formation rests is constantly bringing down masses of it, and mingling 
them with the basaltic, porphyritic, granitic, and calcareous fragments 
which the torrents carry down to the valleys, and, through them, in a 
state of greater or less disintegration, to the sea. The quantity of sand 
annually washed into the Eed Sea by the larger torrents of the Lesser 
Peninsula, is probably at least equal to that contributed to the ocean by 
