RECLAMATION OF THE SOIL. 



35 



planks they are pulled up about 3 feet by means of 

 levers, and this process is repeated until the artificial 

 dune has reached such a height that no sand can be 

 carried over the top (see Fig. 16). Simultaneously with 





Fig. 16. 



n. Sea level. 



b. Paling in three successive positions. 



c. First wattle fence. 



d. An additional wattle fence. 



e. Original surface of littoral dune. 



, g. Surface of littoral dune in two subsequent stages. 



(The heights are exaggerated.) 



the first erection of the paling a wattle fence is placed 

 at a convenient distance behind it, to prevent the sand 

 which has passed through the paling from being carried 

 inland; when the first wattle fence has been entirely 

 covered, a fresh one is made to replace it. In this way 

 the dune is forced to adopt a moderate slope on both sides, 



D 2 



