390 PHYSICAL GEOGRAPHY. 



Years. 



1726. A violent storm changes the salt marsh of Araya, in the province of 



Cumana, into a gulf several leagues wide. 



1770 1785. Currents and tempests hollow out a channel between the high and the 

 low parts of Heligoland, and transform into two islets this island, so 

 extensive before the eighth century. 

 1784. A violent storm, according to M. Hoff, forms the lake of Aboukir, in 



Lower Egypt. 

 1791 1793. New irruptions destroy the dykes, and carry off other parts of the already 



reduced island of Nordstrand. 

 1803. The sea sweeps away the last remains of the priory of Crail, in Fifeshire. 



The most remarkable alteration of the coast line mentioned in this record, as the effect 

 of a sudden invasion of the ocean, is that which originated the present Zuider Zee, or 

 the South Sea, so called to distinguish it from the North Sea, or German Ocean, a great 

 gulf dividing Friesland, Drenthe, and Gelderland from Holland and Utrecht. This 

 gulf covers an area of about 12,000 square miles, and is about twice the size of the 

 county of York. It was not in existence in the time of the Romans, but a low swampy 

 marsh occupied its place, drained by the river Yssel. In this district there were several 

 lakes, particularly the great lake Flevus, mentioned by Tacitus and Pomponius Mela. 

 The former relates the arrival at it of the Roman fleet under Germanicus, through the 

 canal of Drusus, an artificial branch connecting the Rhine and the Yssel. No material 

 change appears to have occurred here before the commencement of the thirteenth century. 

 Then the sea broke over the isthmus which connected Friesland with North Holland, 

 ultimately cut it away, forming the present Straits of Staveren. The lake Flevus was 

 absorbed, a considerable portion of the surrounding country was submerged, and the 

 Zuider Zee was constructed by the advance of the ocean in the form and depth which 

 it still preserves. If, as the Persic verses affectingly state, describing the transitory 

 nature of human greatness, 



" The spider has wove his web in the imperial palace, 



And the owl hath sung her watch-song on the towers of Afrasiab, 



it is no less true that the features of nature have alternated as strikingly, marine inha 

 bitants sporting in sites where land animals have roamed in sylvan scenes ; and we may 

 fairly accept these changes, which are known to have transpired since the date of 

 authentic history, as samples of the revolutions that occurred at a more remote period, 

 of which no chronicle has been preserved. It has been supposed, that as the Straits of 

 Staveren were closed prior to the thirteenth century, the sea then cutting its way 

 through the isthmus, so were the Straits of Dover once occupied by an isthmus, 

 connecting the coasts of England and France, which a violent irruption of the ocean 

 partially destroyed, and then gradually scooped out the present channel. There is 

 nothing contrary to the analogy of undoubted physical events in this supposition, and it 

 is supported by some striking evidence. Desmarest argued in its favour from the 

 identity of the cliffs in composition on each side of the channel, from the fact of a 

 submarine chain running from Boulogne to Folkestone only fourteen feet under low 

 water, and from the circumstance that the same noxious animals are common to both 

 countries, which could never have themselves effected the passage of the straits, and 

 which man would not have introduced. 



The bolder coasts seem to present an impregnable front to the attack of storms and 

 tempests, both by their height and the rocky materials of which they are composed ; yet, 

 however they resist the farther progress of the waves, when the sea, swollen by tides. 



