AETinCIAL BEEAKWATEES. 



159 



by the waves. By employing the heroic means which the English 

 engineers have applied to the defence of Shakspeare's Cliif, and 

 which the garrison of Heligoland had also inaugurated in the year 

 1808, by bombarding a crumbling cliff,* the inhabitants might sur- 

 round their island with a great circular breakwater. But this dike 

 would not last long, for the strata of mottled stone do not contain 

 those beds of pebbles which serve to form shingle for a beach. 



b'35' 



Fig. 64.— Heligoland. 



Hallier, Nord-See Studien, p. 73. 



