214 Forest Trees of Massachusetts. [April, 



sometimes it is impossible, Avitliout protection. But a low wall 

 of loose stones seaward, is sufficient to protect young trees near it 

 until they get a little higher than the wall. The successive rows 

 inland will be better protected, and will rise each higher than the 

 preceding; until at the distance of a few rods, they may rise to a 

 tolerable hight. When a belt of trees is once established, in such 

 a situation, it should be kept undisturbed as long as it will serve 

 the purpose of protecting the trees within, though it may be of no 

 other value. 



"A course altogether similar should be taken in planting a much 

 exposed hill. By beginning at the bottom and gradually planting 

 upwards, the top may at last be clothed ; as every belt of trees of a 

 few feet in hight, will protect a younger one a little higher on 

 the hill. 



"Wherever trees are planted for use in the arts, it is important 

 to give them the most rapid growth possible. Of wood growing 

 on the same soil, that which growls the most rapidly is strongest. 



"That of which the circle of growth is narrowest is also weak- 

 est.* This fact is familiary, known to ship-builders, makers of 

 lasts and trenails, and of all of those articles which require great 

 strength. The reason is obvious. The circles of annual growth 

 are separated by zones of loose, porous structure and inferior 

 strength. 



"The strength of wood is proportioned to its weight. And as 

 young trees grow more rapidly than old ones, they are more 

 valuable as fuel. Round wood of oak or maple gives more heat 

 than that which is so large as to require to be split. This fact 

 shows the wastefulness of burning on the ground the undergrowth 

 and the trimmings, in clearing for cultivation or cutting for cord 

 wood. Heart wood is heaviest, and the weight diminishes on 

 proceeding outwards to the surface or upwards to the top of the 

 tree, but much less in old trees than in young growing ones. The 

 sap wood of oak was found by Decandolle to fall short of the heart 

 wood in weight, in the proportion of 6 to 7. 



"It has long been known that summer or early autumn is the 

 season most favorable for the felling of timber, where the object 

 is strength and durability. One reason why timber has not 

 usually been cut at that season is, that most of those who fell trees 

 are at that season occupied with their farming. The felling of 

 trees is their winter employment. Nearly a quarter of a century 



* Buffon, II., 307. A circle of wood is annually formed on the trunk of a 

 tree, between the oute^ previous circles and the inner bark. The space in- 

 tervenin!^ between the annual circles or layers, is loose and porous, and con- 

 tains very little solid substance or strenijtli. The more frequently, therefore, 

 these weak spaces succeed each other in u given thickness of wood, the less 

 must be the solidity and strength of the wood. 



