Description of the Landes of Acquitania. 101 
records of history, in the physical indices of the country, and often 
in the oral traditions:of the people: though their motions are not 
as those of the tempest or the whirlwind, but slow and insidious ; 
for the sands of the ocean will, in their silent progression, . bury a- 
forest while they scarcely disturb the leaf of a tree. 
The attention of agriculturists was soon directed to an object of 
so much importance. ' The aid of natural history was claimed, and, 
in almost all the litoral countries of Europe, prizes have been offer- 
ed for proposals to arrest these alarming invasions. It is evident 
that, the action of the water continuing the same, a similar quan- 
tity of sand must be deposited, and downs or hills will result from 
its accumulation ; the question is therefore only how to arrest their. 
further progress. 
On the northern coasts of the Firth of Forth, where the progres- 
sive advance of the sands is slow, the stoppage is in the most part 
effected by nature; the Arundo arenaria growing in successive 
crops, gaining such strength as to overtop the sands in their next 
advance, and assisting towards the elevation of the downs. But 
it does not follow, that plants of this nature are always capable 
of arresting the encroachment of the ocean’s sands; for many 
facts prove to the contrary. From the very principle of its 
erowth, and from the-manner in which it overtops the sand, its 
long culm becoming blanched, and performing the part of a root, 
while the lengthened stalk sends out new verdant leaves, it breaks 
the sands, and arrests their motions. If the latter were in such 
quantities as to bury the whole plant, its dissemination would be 
of little use. Hence in the rapid formations, and the sudden 
changes which mark the progress and existence of the downs on the 
shore of the Bay of Biscay, a formidable opponent is met with to 
the use of such simple means, and methods more adapted to the 
energies of the circumstances are put in force. 
In most parts of these tracts, no attempt is made to regulate 
either the formation or the motions of the first ranges. They are 
regarded as truly under the dominion of the winds and waves, and 
beyond the control of man; and it is only on their advance into 
the interior, that a barrier is placed by extensive plantations, dis- 
seminated first in the vallies, and drawn gradually up the acclivi- 
ties, even to the summits of the inland ranges. Near Mimizan, 
planks of deal are, at government’s expense, forced into the sands 
in regular order, and close opposition. On the accumulation of 
sand taking place up their sides, they are elevated higher and high- 
er, and thus artificial downs are gradually formed. 
Clayonnage is also employed ; it consists in forming on the sur- 
face small compartments in clay and straw, from 12 to 18 inches in 
height, parallel to the direction of the winds which most frequent- 
ly prevail, and sowirtg between them Arundo arenaria, Elymus are- 
narius, and arborescent leguminosz, as the great Ulex, species of 
Genista, Spartium, &c. These plants maintain the soil, te which 
the nine tree is afterwards confided,. ; 

