96 ECOJ!fOMICAL GEOLOGY. 



of importance in protecting the marshes behind them and 

 the main land. In some foreign countries, forests have 

 been cultivated for the purposes of fixing such loose sands. 

 Boussingault, in his " Rural Economy," p. 237, says : — 



" It is a problem of the highest importance, in many 

 instances, to fix permanently masses of sand blown up 

 from the sea, by covering them with productive planta- 

 tions. This problem was studied and successfully resolved 

 by M. Bremontier, a French engineer. Aware that cer- 

 tain plants thrive in the sands of downs, he saw that they 

 alone were capable of staying their progress and consolidat- 

 ing them. The grand object was to get plants to grow in 

 moving sand, and to protect them from the violent winds 

 which blow off" the ocean, until their roots had got firm 

 hold of the soil. 



" Downs do not bound the ocean like sea-beaches. From 

 the base of the first hillocks to the line w^hich marks the 

 extreme height of spring-tides, there is always a level over 

 which the sand sweeps without pausing. It was upon 

 this level space that Bremontier sowed his first belt of 

 pine and furze seeds, sheltering it by means of green 

 branches fixed by forked pegs to the ground, and in such 

 away that the. wind should have least hold upon them, 

 viz: by turning the lopped extremity toward the wind. 

 Experience has shown that by proceeding thus, fir and 

 furze seeds not only germinate, but that the young plants 

 grow with such rapidity, that by-and-by they form a thick 

 belt a yard or more in height. Success is now certain. 

 The plantation, so far advanced, arrests the sand as it 

 comes from the bed of the sea, and forms an effectual bar- 



