XXXVI Appendix. 
through the spaces left between the planks, and serves as a sort of backing, 
thus increasing their stability. When the sand reaches the top of the 
paling, and begins to cover it, the latter is raised by means of a lever with 
hooks. In this manner the littoral dune rises higher. This increase in 
height must be rendered as gradual as possible, otherwise the dune would 
be exposed to be washed away by the sea. 
** To give the dune more stability, a tight-bound fence is erected behind 
the paling. Stakes 2:50 métres in length are driven 50 centimétres into 
the sand, and the wattling is at first carried only up to a métre above the 
ground. The wattling is continued upwards as the dune rises. When the 
dune reaches the top of the stakes, another fence of the same kind is put 
up, for the old fence obviously cannot be raised like the paling. 
“The whole is at length fixed by planting over with the Psamma 
arenaria in tufts of five or six plants 50 centimètres (20 inches) apart. 
This grass possesses this important property, that, as the sand covers it, 
its stalk grows higher, and developes numerous adventitious roots, which 
form a veritable network. A hectare requires 300 bundles of this plant, 
weighing 10 kilogrammes (22 lbs.) each, besides 6 kilogrammes (18 Ibs.) of 
seeds. The first thing done is to sow the seed broadcast, the operation of 
planting, and the going to and fro of the labourers, being enough to press 
them into the ground. 
“ A running metre of paling costs from 2-50 to 8 francs (about 8d. per 
ruuning foot). It lasts, on an average, five years, when the planks are 
made of the non-injected sapwood of the Pinus pinaster. The expense of 
keeping it in repair and raising it is about 50 centimes a-yeat (about one 
penny and a fifth per running foot). The price of a métre of fencing is 
30 centimes (about 0-88d. per foot), and a new fence must be put up nearly 
every year. 
“If, notwithstanding these precautions, the wind is apt to make 
breaches in the littoral dune, other rows of paling, making a given angle 
with the first, are erected on the steep side. At the present day may be 
seen a littoral dune, well kept up along a coast-line of more than 200 
kilométres, reaching from the bar of the Adour to the mouth of the 
Gironde. 
“ A protecting wall against the wind being once obtained, the moment 
has arrived for beginning sowing operations on the inner dunes. This is 
done by scattering broadcast a mixture of the seeds of the Pinus pinaster, 
the common broom ( Sarothamnus scoparius), the furze (Ulex nanus ), and 
the Psamma arenaria. In the operations earried on by the State, the 
quantity of seed to be used per hectare is 10 kilogrammes of the pine, 
9 kilogrammes of the broom, and 4 kilogrammes of the Psamma arenaria, 
