THE BRITISH ISLES. 



In its general features the bed of the North Sea resembles the mud-flats, or 

 trodden, of its eastern shore. Oceanic currents have scooped out channels in the 

 mud and sand, but the ori<jinal relief of the sea-bed has been obliterated. A 

 submarine plain like this can be the product only of causes acting uniformly 



Pig. 1.— The North Sea. 

 Scale 1 : 7,400,000. 



XrrMUn of Parti 



Mrriilinii of GrepiKrich 



\ Dtcth InFàthom f- I 



iTtoii 64tOllO 



100 MUes. 



over a wide area ; and for such a cause the majority of geologists go back to the 

 glacial epoch, when glaciers, laden with the waste of the land, drifted into this 

 ancient gulf of the Atlantic, and there deposited their loads.* Even at the present 

 day there are agencies at work which tend to fill up the basin of the North Sea. 

 • Eamsay, "Physical Geologj' and Geography of Great Britain." 



