FORESTRY IN FRANCE. Zo 
forest were felled only once in every 100 or 150 years; and it is 
chiefly to avoid this that a working plan is required, which pre- 
scribes the arrangement necessary in order to allow of the produce 
being taken out annually, without intermission and in equal quan- 
tities, so that a regular and sustained income may be drawn from 
the forest. For example, a simple coppice thirty acres in extent, of 
which the crop is to be felled at the age of thirty years, might 
either be entirely cut down at one time, and then allowed to grow 
up again for thirty years; or, which would be found much more 
convenient, it might be divided into thirty one-acre compartments, 
each of which is to be felled in succession, so that by taking one 
plot each year, the whole area would be worked over in thirty 
years. The working plan must then, in the first place, prescribe the 
age at which the trees are to be felled, with reference to the average 
number of years that they take to arrive at maturity, or to attain 
the required size ; and it must then fix the yield, or the amount of 
wood to be annually removed, this quantity being expressed either 
in the form of an area to be cut over, or a number of cubic feet of 
wood to be taken out. But in the case of a high-forest managed 
under the selection method, it is sufficient to fix the number of trees 
of a minimum size to be cut out annually. 
The provisions of a working plan vary according to the nature of 
the forest to which it relates. In the case of the simple coppice 
instanced above, the first thing to do would be to obtain a map (see 
Pl]. VII.) showing the principal features of the ground, such as the 
edge of the plateau, the stream, and the road. The area would then 
be broken up, for purposes of examination and description, into 
temporary plots, such as those lettered from (A) to (H), each plot 
comprising a portion of forest more or less homogeneous in its com- 
position. This study of the crop would enable the area to be 
divided into the thirty permanent compartments above alluded to, 
and it would also determine the order in which they should be 
numbered, so that the older portions might be cut first. It is 
evident that if one of these be cut every year, the series of compart- 
ments will, after the lapse of thirty years, contain forest of all ages 
from one to thirty years; and if the annual felling be invariably 
made in the oldest compartment, it is evident that the age of the 
crop cut will always be thirty years. 
To make a working plan fora regular high-forest, to be treated by 
successive thinnings, is not quite such a simple matter. If the forest 
is of great extent, it is, first of all, divided into two or more series or 
VOL. XI., PART II. R 
