THINNING AND PRUNING. 30 
rived at the conclusion that nothing contributes so much to the 
solidity, strength and durability of timber, as completely strip- 
ping the trees of their bark, some years,—at least three, before 
they are to be felled. ‘This should be done in the spring, when 
the bark is most easily separable. ‘The tree continues to put 
forth leaves, and to expand and mature them for several suc- 
cessive seasons. But as no new wood can be formed, after the 
bark is removed, Buffon supposed that all the action of the 
leaves goes to add to the substance of the wood previously 
formed.* It is thus increased in density and weight; and he 
found that, universally, in the same kind of wood, strength is 
proportional to weight. By this process, the sap-wood was ren- 
dered as dry, hard and strong, as heart-wood, and in some 
instances even stronger. ‘Timber managed in this way was 
found to be sometimes a fourth part stronger than that from 
trees in the same forest, and in all other respects precisely sim- 
ilar, treated in the usual way; that is, felled with the bark on, 
and dried under the open sky or under sheds.t 
Such are some of the suggestions which I have desired to lay 
before my fellow-citizens of Massachusetts, for the improvement 
of their forests and the redemption of their waste lands. I have 
opened, very imperfectly, the great and important study of the 
history and management of forest trees. A tree is the most 
magnificent among the material works of God. The nature, 
the relations to soil, to climate and to exposure, the affinities, 
the properties and the uses to man and other animals, the dan- 
gers from enemies and diseases within and without, and the 
circumstances necessary to secure the health, growth and beauty 
of the trees of any one family, are subjects worthy of the delib- 
erate and mature and long contmued attention of any man, of 
whatever intelligence, and with whatever resources of science. 
The best disposition of trees in the landscape, the treatment of 
each according to its character and appearance at all seasons of 
* This it probably does by appropriating the substance destined for new layers of 
wood, to ming and filling up the cells or tubes, of which woody fibre is composed. 
+ See Buffon, Tome IL., edition de Richard, 1839. Expériences sur les Végétaux. 
Second Mémoire, p. 325, et suivantes. 
