SALT MARSHES -PAST AND FUTURE 



attacked the ancient Britons in the highlands 

 at Reedham and JSTorwicli, now eighteen miles 

 from the sea, and here they '' buylded toures 

 on the clynes of the ocean in dy verse places." 

 One may read in the Saxon Chronicle that 

 in the year 1004, Sweyn with thirty ships 

 plundered and burned Norwich. Even as late 

 as 1327 it is stated that Norwich i.= " situate 

 on the bank of a water and arm of the sea, 

 upon which ships, boats and other vessels have 

 immemorially come to their market." 



Accumulations of silt and the growth of 

 vegetation, narrowing these estuaries into 

 sluggish streams, with here and there dwin- 

 dling sheets of shallow water called broads, 

 can be explained by the cutting off of the sea 

 and tidal currents owing to the formation of 

 sand-bars and later of dunes at the mouths 

 of the rivers. The most famous of these sand- 

 bars is the one on which the fishing town 

 of Great Yarmouth now stands. Even before 

 the Norman Conquest the sand-bar at this 

 point had become a sand bank frequented by 

 fishermen. Later man cooperated with the 

 ocean by bmlding dykes and drains and erect- 

 ing wind and steam pump-mills still more to 

 exclude the salt water, and hasten the depo- 



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