196 ON ALLUVIAL FORMATIONS. 



and tearing away the grass which had bound their sur- 

 face, they were reduced to the state of mere banks of 

 sand and mud, whence they had been drawn, by the long 

 course of ordinary causes. Such were the dreadful acci- 

 dents to which the first settlers on these lands were ex- 

 posed ; but no sooner were they over, than ordinary 

 causes began again to act ; the sand-banks rose ; their 

 surface was covered with grass ; the coast was thus ex- 

 tended, and new islands were formed ; time effaced the 

 impression of past misfortunes ; and those among the in- 

 habitants of these dangerous soils, who had been able to 

 save themselves on the coast, ventured to return to settle 

 on them again, and had time to multiply, before the re- 

 currence of the same catastrophes. 



This has been the general course of events on all the 

 coasts of the North Sea, and particularly on those of the 

 countries of Sleswigh and Holstein. it is thus that the 

 origin and progress of the art of dikes will supply us with 

 a very interesting chronometer in the history of the conti- 

 nent and of man, particularly exemplified in this part of 

 the globe. A Lutheran clergyman, settled in the island 

 of Nord Strand, having collected all the particulars of 

 this history which the documents of the country could 

 afford, published it in 1668, in a German work, entitled 

 The North Frisian Chronicle. It was chiefly from this 

 work, and from the Chronicle ofDankwerth, that M. Hartz 

 extracted the information which he gave to me, accom- 

 panied by two maps, copied for me, by one of his sons, 

 from those of Johannes Mayerus, a mathematician ; they 

 bear the title of Frisia Cimbrica ; one of them respecting 

 the state of the islands and of the coast, in 1240, as it may 

 be traced in the chronicles, and the other, as it was in 

 1651. 



