146 PRACTICAL FORESTRY 
in a roomful of men there are several obnoxious per- 
L: Bost een 
cleaning ”’; 
sons, their removal would constitute a’ 
if, on the other hand, because of a lack of room the 
reduction of the number became necessary, the re- 
moval of every other person, or every third or fourth 
* In thinning, 
person, would constitute a ‘“ thinning.’ 
however, as in cleaning, although the object is pri- 
marily the reduction of population for the sake of 
space, a process of selection may be practised by re- 
moving the least desirable members of the commu- 
nity whenever this is possible. 
A single tree in the open produces much more 
wood than it would in the forest. The quality of 
the wood produced in the open is of course poor. 
Sometimes only fuel-wood may be the object, some- 
times also living knots may be desired to produce a 
figured board, but this is of course comparatively 
seldom. The largest amount of poor wood per acre 
may be produced in the shortest length of time from 
coppice. A large amount of medium-grade wood may 
be produced in a comparatively short time in open 
woods where each tree may have plenty of space in 
which to grow, and in which there is a large percent- 
age of limbage. The largest quantity of good wood 
can be produced in a closed forest, where thinning 
is carefully practised, and where the canopy is kept 
in such shape that the stems will shed their limbs as 
