PLAINS OF THE ELBE AND WESER, ETC. 275 



many places has recovered the ground it lost formerly. Mediaeval chronicles 

 record many disasters caused by sudden irruptions of the sea. In 1066 the sea 

 invaded the gulf of the Jade, sweeping away the castle of Mellum, whose site is 

 still indicated by a sand-bank bearing its name. Fresh irruptions of the sea 

 in 1218 and 1221 scooped out what is now the deepest part of the gulf, to the 

 south of Wilhelmshafeu. More disastrous still were the floods of 1277. A 

 fearful tempest forced the sea up the estuary of the Ems, where it swallowed up 

 forty villages and formed the sinuous gulf of the Dollart. Another disaster 

 happened on the 1st of November, 1570, when the sea forced the dykes from 

 the mouths of the Meuse to the Forest of Skagen, destroying 100,000 human 

 beings ; and many times since then has the sea broken through the embankments 

 erected as a protection against it, involving numerous villages in ruin. A slow 

 subsidence of the land probably accounts for these irruptions. M. Prestel has 

 computed the annual advance of the sea along the coast extending from the Texel 

 to the northernmost cape of Denmark at 18 feet, which must have resulted in a 

 loss of 1,500 square miles since the thirteenth century. 



But whilst the sea thus encroaches upon the coast, there are agencies at work 

 which result in the formation of new land. In the estuaries of the Ems and 

 Weser, and near the mouths of the smaller rivers, where salt and fresh water 

 mingle, the matter held in suspension is deposited before the turn of each tide ; 

 and not only do small particles of sand and clay sink to the bottom, but some 

 chemical process goes on simultaneously, the salts of lime and magnesia mingling 

 with the ooze. At the same time innumerable infusorial animals, which die in 

 the brackish water, and myriads of marine organisms, which are killed by the 

 fresh water of the rivers, sink to the bottom, forming, in the course of ages, thick 

 layers of wonderfully fertile soil. Professor Ehrenberg states that the ooze, or 

 Schlick, in the bays and port of Emden consists, to the extent of three-fifths of its 

 volume, of the remains of animalculao. Amber was formerly found on the shores 

 of the North Sea. This amber contained none of the insects so frequently met 

 with in that of the Baltic, and it has hence been concluded that the coast of 

 Friesland w^as as poor in beetles at that epoch as now. 



When the mud-banks first emerge from the water they become covered with 

 saline plants. After awhile sedges and clover make their appearance, and it 

 is then that man first attempts to secure these rich lands, which, once embanked, 

 yield harvest after harvest for a century, without requiring any artificial manure. 

 Originally a family of the Geest, desirous of embanking a mud-bank, esta- 

 bliahed itself upon an old island, beyond the reach of the flood, or constructed 

 a urirffn, or wharf, placing it beyond the reach of the sea. For ages, however, 

 the work of embankment has been taken in hand collectively, and the dykes of 

 German Friesland are no less remarkable than those of the neighbouring 

 Netherlands. Most of them average between 15 and 30 feet in height, but 

 there are some as high as 40 feet, and their maintenance has beea very costly. 

 But the inhabitants are obliged to construct dykes, or to go away : — 



"De nich will diken, mut wiken." 



