134 THEORY OF THE EARTH. 



middle age ; and at this moment, in the single 

 Department of the Landes, they threaten ten 

 with inevitable destruction. One of these villages, 

 named Mimisan, has been struggling against 

 them these twenty years, with the melancholy 

 prospect of a sand-hill of more than sixty feet 

 perpendicular height visibly approaching it. 



In 1802, the pent up pools overwhelmed five 

 fine farming establishments at the village of St 

 Julian *. They have long covered up an ancient 

 Roman road leading from Bourdeaux to Bayonne, 

 and which could still be seen forty years ago, 

 when the waters were low f . The Adour, which 

 is known to have formerly passed Old Boucaut, 

 to join the sea at Cape Breton, is now turned 

 to the distance of more than two thousand 

 yards. 



The late M. Bremontier, inspector of bridges 

 and highways, who conducted extensive opera- 

 tions upon these downs, estimated their progress 

 at sixty feet yearly, and in some places at seventy- 

 two feet. According to this calculation, it will 

 only require two thousand years to enable them 

 to reach Bourdeaux ; and, from their present ex- 

 tent, it must have been somewhat more than 



* Memoir on the means of fixing Downs, by M. Bremon- 

 tier. 



t Report of M. Tassin, loc. cit. 



