ARREST OF MOVING SANDS. 237 



Downs do not bound the ocean like beaches. From the base of 

 the first hillocks to the line which marks the extreme height of spring 

 tidee, 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 a way 

 that the wind should have least hold upon them, viz., by tu.-ning the 

 lopped extremities towards 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 and 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 barrier to the other belts 

 that are made to succeed k towards the interior. When the trees 

 are five or six years of age, a new plantation is made contiguous to 

 the first and more inland, from 200 to 300 feet in breadth, and so 

 the process is carried on until the summits of the hillocks are gradu- 

 ally attained. 



It was by proceeding in this way that Bremontier succeeded in 

 covering the barren sands of the Arrachon basin with useful trees 

 Begun in 1787, the plantations in 1809 covered a surface of between 

 9,000 and 10,000 square acres. The success of these plantations 

 surpassed all expectation ; in sixteen years the pine trees were from 

 thirty-five to forty feet in height. Nor was the growth of the furze, 

 of the oak, of the cork, of the willow, less rapid. Bremontier show- 

 ed for the first time in the annals of human industry, that moveable 

 sands might not only be stayed in their desolating course, but actu- 

 ally rendered productive. Like all other inventors, this benefactor 

 of humanity was soon the object of jealousy among his contempora- 

 ries. Doubts were of course entertained at first of the possibility 

 of consolidating the moving sands of downs ; and when this was de- 

 monstrated, the honor of originality was denied him. The ingenious 

 engineer defended himself with moderation, and demanded an in- 

 quiry ; in the course of which it was satisfactorily proved that noth- 

 ing of the same kind had been attempted by others previously to the 

 year 1788. The labors of Bremontier must be regarded as another 

 of those remarkable struggles which the industry of man has suc- 

 cessfully waged with the elements. 



CHAPTER V. 



OF MANURES. 



Whatever may be its constitution and physical properties, land 

 yields lucrative crops only in proportion as it contains an adequate 

 quantity of organic matter in a more or less advanced state of de- 

 composition. There are favored soils in which this matter, desig 



