88 J. H. MAIDEN. - 
the sand. As the sand rises, the Marram, even if tempor- 
arily submerged, will push its way up and continue to grow. 
Finally, by judicious planting of the Marram, and encour- 
agement of it, it is possible to obtain the ‘‘ constant” for 
a particular spot, indicative of the height beyond which 
sand from the sea shore or other source is incapable of 
passing. When this is obtained, the “‘ dune littorale ”’ can 
be formed, and its fixation and maintenance arranged. 
The dune littorale must have a surface as regular as 
possible, otherwise the wind speedily accentuates the 
unevennesses and creates ridges and depressions in the 
mobile sand which steadily increase in size. The profile 
of the dune littorale must be decided upon according to 
local experience. In regard to this, as indeed in regard 
to other points in connection with sand-dunes the personal 
experience and responsibility of the forester must be 
exercised. 
b. Fixing the sand by means of vegetation.—In France 
the fixation of the sand by mechanical means and the per- 
manent fixation by means of a permanent crop of trees 
proceed simultaneously; it is obvious that the one may 
precede the other. In France not only is fixation of the 
shifting sands readily accomplished as part of the ordinary 
business of the forester, but a timber crop is raised upon 
these hitherto waste lands. The chief timber tree is the 
Maritime or Cluster Pine (Pinus pinaster, Sol.; P. mar- 
itima, Poir). The trees are not only tapped for the tur- 
pentine they contain, a flourishing industry being the result, 
but the timber has considerable local value, and is even 
exported to Hngland, chiefly for mining purposes. 
‘*As regards the species there was little doubt. “Cluster 
Pine,’ the ‘ Pin Maritime,’ was already flourishing in places 
in the Landes.’’ Whata lesson we have here! The saga- 
cious Frenchman uses his native and well acclimatised 
: 
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