1N8TBU0TIONS GIVEN IN SCHOOL OP FORESTRY. 137 



more room to extend their branches, in a short time give to the 

 ground a thick cover, while, on the other hand, they form a fine 

 conical head, such as ensures a good ultimate growth, and at the 

 same time a stem more thick and short, and strong enough to bear 

 up under the weight of the snow. 



*' The subsequent thinnings ought to succeed each other at 

 moderate times apart, which will have effect of rendering them less 

 productive ; but in their entirety they will yield more, and exercise 

 on the vegetation of the stems, destined to grow to the completion 

 of the cycle, the salutary influence for which such thinnings are 



" The wood of the pin sylvestre is used both in building and in 

 manufactures, as balks, beams, boards, planks, staves, shingles, etc. 

 When it has attained its maturity it is considered as solid and as 

 durable as that of the oak. In ship carpentry and wooden bridge 

 building it is used as flooring ; and it is almost the only tree of which 

 masts are made. For this use it is obtained in France from the 

 north of Europe. It is only in the higher regions of the principal 

 mountain ranges, where the growth is slow, and the ligneous fibre very 

 dense, that there is a hope of timber being produced of the degree of 

 suppleness and elasticity required for masts. And attention is being 

 given to the seeking out sheltered spots in these regions where the 

 tree will be comparatively safe from snow-loads and hoar-frosts, with 

 a view to the cultivation of forest masses destined to meet this 

 important public requirement.* 



" The firewood furnished by this tree is very superior to what is 

 supplied by some others of the coniferae ; and charcoal produced by 

 it is in demand for forges. 



*' The pin sylvestre produces one portion of the pitch and tar made 

 use of in the French navy. 



" It is the stumps and roots which yield most of this, which is 

 abstracted by subjecting them in furnaces to a slow and gradual 

 distillation. 



"The wood thus deprived of resinous matters is reduced to a 

 charcoal which is used for various purposes. And there are in many 

 countries very productive contract sales of the stumps of this tree, 

 with the privilege to erect such furnaces. 



* A valuable memoir on this subject by MM. Bravais and Martina appeared 

 in the second volume of the Annales Foreati^res, 1843, pp. 369-561. 



