58 



THE OCEAN. 



roadstead, are not less than from 80 to 90 cubic yards. And yet even 

 this strong wall would not be strong enough, if it was not addition- 

 ally defended by stones scattered loosely here and there, forming a 

 range of protecting rocks in front of the dike upon which the sea 

 expends its fury. 



Fig. 21.— Bay of Saint Jean-de-Luz. 



The only places where the waves display a still greater power 

 than in the Gulf of Gascony, are those that are sometimes ravaged by 

 the tornados. In the Isle of Reunion there is to be found in the 

 middle of a savannah, a massive block of madreporic stone, which is 



