802 REPORT OF COMMISSIONER OF ‘FISH AND FISHERIES. [50] 
cultivation may be from all points of view, it is best, perhaps, that the 
small oyster-culturist, to whom this book is especially addressed, should 
look to these bottoms only for his germs, and carry on the breeding and 
fattening entirely in parks or live-ponds, where, master of the water 
which fills them, he can easily follow his products in the successive 
phases of their development, and give to them, from time to time, and 
without very much trouble, all the care they may demand. The culti- 
vation of the constantly submerged bottoms belongs properly to the 
State. : 
ARTIFICIAL BASINS. 
Claires, live-ponds, parks, &c.—For a long time past the breeders of 
Marennes, at the mouth of the Seudre, have employed, for fattening and 
perfecting oysters, artificial basins called claires, a description of which 
we now propose to give. Recommended by a long experience, they seem 
to us, save for the necessary improvements which we shall mention, 
the best model to follow in the construction of artificial breeding-ponds. 
The claires are basins of variable form and extent, but generally with 
an area of about two to three hundred square meters (about the same 
number of square yards). Situated at a short distance from the sea, and 
with the waters they contain at a higher level than the mean height of 
ordinary tides, it is only at the period of the spring-tides, or at each new 
and full moon, that the sea rises to their level and supplies them anew 
with water. The best claires are those which receive water periodically 
from the sea, during about three days before and three days after each 
highest tide. This period of renewal for the eclaires is that which expe- 
rience has found to be the best, and it determines the maximum altitude 
above the sea for the construction of these reservoirs. 
Around each claire is built a levee or dirt wall, called a yard, about 
one meter in height and thickness. This yard retains the water fill- 
ing the basin, and upon it the workmen pass to and fro in inspecting 
and working the claire. A flood-gate closes a sluice in one side of the 
wall, by means of which the sea water is admitted to the basin. This 
gate also regulates the height of water within the basin, and if de- 
sired, the basin can be entirely emptied by opening it wide. All around 
the inner circumference of the yard a continuous trench is dug, to re- 
ceive the mud deposited in the basin from the stagnant water, for if 
this mud should be left in the basin the oysters would soon be smoth- 
ered. In order to facilitate the clearing away of the mud into this ditch, 
a slight slope is given to the bottom of the basin, circumscribed by 
the ditch, from the center towards the borders, so that the surface is 
sensibly convex. Some breeders dispense with this ditch; in which 
they are probably wrong, for if it does not prevent the deposit of mud, 
it at least retards it and lessens its effect. Its use cannot be judiciously 
dispensed with, unless the water has a long distance to run from the 
sea and is given a chance to settle before being admitted to the claire, 
