414 CONSTRUCTION OF DIKES. 
than against the waves, and the inner slope is always compara- 
tively abrupt. 
The height and thickness of dikes varies according to the 
elevation of the ground they enclose, the rise of the tides, the 
direction of the prevailing winds, and other special causes of 
exposure, but it may be said that they are, in general, raised 
from fifteen to twenty feet above ordinary high-water mark. 
The water-slopes of river-dikes are protected by plantations of 
willows or strong semi-aquatic shrubs or grasses, but as these 
will not grow upon banks exposed to salt-water, sea-dikes must 
be faced with stone, fascines, or some other vrevétement.* 
Upon the coast of Schleswig and Holstein, where the people 
have less capital at their command, they defend their embank- 
ments against ice and the waves by a coating of twisted straw 
or reeds, which must be renewed as often as once, sometimes 
twice a year. The inhabitants of these coasts call the chain of 
dikes “the golden border,” a name it well deserves, whether 
we suppose it to refer to its enormous cost, or, as is more 
probable, to its immense value as a protection to their fields 
and their firesides. 
When outlying flats are enclosed by building new embank- 
* The dikes are sometimes founded upon piles, and sometimes protected 
by one or more rows of piles driven deeply down into the bed of the sea in 
front of them. ‘‘ Triple rows of piles of Scandinavian pine,” says Wild, 
‘““have been driven down along the coast of Friesland, where there are no 
dunes, for a distance of one hundred and fifty miles. The piles are bound to- 
gether by strong cross-timbers and iron clamps, and the interstices filled with 
stones. The ground adjacent to the piling is secured with fascines, and at 
exposed points heavy blocks of stone are heaped up as an additional protec- 
tion. The earth-dike is built behind the mighty bulwark of this breakwater, 
and its foot also is fortified with stones.” . . . ‘‘ The great Helder 
dike is about five miles long and forty feet wide at the top, along which 
runs agood road. It slopes down two hundred feet into the sea, at an angle 
of forty degrees. The highest waves do not reach the summit, the lowest 
always cover its base. At certain distances, immense buttresses, of a height 
aud width proportioned to those of the dike, and eyen more strongly built, 
run several hundred feet out into the rolling sea, This gigantic artificial 
coast is entirely composed of Norwegian granite.”—Wu1LD, Die Niederlande, i., 
pp. G1, 62. 
