130 NATURAL HISTORY OF 



vast current by means of the new efflux of the Rhine, would 

 give such force to the ebb tide, (now first beginning- to meet 

 the flowing wave in the channel,) that a new aspect would be 

 given to all the shores, even far up the east coast of Britain. 

 Heligoland, a friable conglomerate, became an island at no 

 very remote period. So late as the ninth century of our era, it 

 was still forty times the present area ; in 1300, twelve times 

 the surface ; but woods, rivulets, pagan temples, monasteries, 

 parishes, and castles, have been swallowed up, and the portion 

 still above water gradually crumbles away. When the Cym- 

 bers penetrated into Italy, they had recently been dislodged by 

 great encroachments of the sea on their native shores, which 

 were in the low lands of the above-named rivers, on the north 

 of the kindred tribes of Friesland, who were repeatedly suf- 

 ferers from the same cause, down to recent times. Thus, on 

 the river Unsing, which, in the Roman era, reached the sea by 

 a direct course, and later by the Ems, there is noticed the 

 Portus Manarmanis ; and higher up the bank, a place named 

 Siatulanda, both localities being now lost in the waters of the 

 Dollaert.^ 



THE RHINE. 



The whole delta of the Rhine, by the many changes that 

 have occurred in its several arms within the historical period, 

 through West Friesland, Holland, and Zealand, proves the 

 unconsolidated condition of the deposits; and the depth of 

 alluvial was shown at Amsterdam, in 1604, when a well was 

 sunk, in an abortive attempt to obtain pure fresh water, the 



* If the convulsion, which certainly took place, belonged to so remote a 

 period as a former order of creation, the final effect would have terminated 

 long before our historical era. It is more likely to synchronize with the 

 changes in the Polish and Russian inland seas, when a very considerable 

 alteration must ha 'e resulted in the currents and tides on the west coasts 

 of Europe. 



