60 NATURAL HISTORY OF 



period, covered the drainage of the Elbe, the Weser, 

 and the Ems, &c., more anciently communicating, but 

 imperfectly with the Gallic Sea (perhaps at high water 

 only, through the Belgian low lands, behind the chalk 

 cliffs of the coast, to the Liane, south of Boulogne), sud- 

 denly forming a 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. Heli- 

 goland, 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 Cymbers pene- 

 trated 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 sufferers 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.* 



* If the convulsion, which certainly took place, belonged 

 to so remote a period as a former order of creation, the 



