376 BULLETIN OF THE BUSSEY INSTITUTION. 
There have been many opinions advanced in regard to thinning 
and trimming white pine forests, and these divergent views have 
to some extent been caused by a difference of opinion as to how 
long the trees should be permitted to grow. If a pine forest is to 
be cut when large enough for coarse lumber, it should be treated 
differently from one that is to stand long enough to make clear 
lumber ; but little need be done with the former except to cut out 
the dead and dying trees, while the latter should be carefully 
looked after from the time the trees are eight feet high until the 
limbs on the trunk are all off to the height of twenty or more feet. 
As early in the growth of the forest as possible, the trees that are 
to remain for lumber should be selected and the lower limbs on 
the trunk cut off as fast as it is considered safe to do so and not 
injure the vigor of the tree; this work should be done in June. 
After having chosen the trees that are to make the future forest, 
all the trees between them should be kept back and destroyed as 
fast as they appear to crowd the selected trees; but it is well to 
let the trees between stand quite near to the selected ones until 
they are twenty feet high if they do not overshadow them. By so 
doing the trees will grow higher and the trunks will have fewer 
limbs, thus securing clear lumber ; in fact a good white pine timber 
tree rarely ever grows in an exposed position ; it must grow where 
it is surrounded by other trees or it will not make a long, straight 
and clear timber log; he who is to trim a timber lot must ever 
keep this fact in mind, and do his work in such manner as will 
best assist nature in her efforts to produce trees of the best type 
for man’s use. It is not wise to attempt to grow more than 160 or 
170 timber trees to the acre, but by the selection of this number 
when the forest is young, they may be given ample room to de- 
velop, and there will be left room between them to grow a limited 
number of trees large enough for box-boards. 
