296 A MANUAL OP FORESTRY. 



in many cases it improves the quality of the timber 

 considerably. 



Thinnings generally commence at the age of 20 to 

 25 years ; they should be light, and frequently repeated 

 up to the age of 50 years. This is necessary, as snow 

 breakage may occur during this period, followed by a 

 considerable interruption of the cover. After the age of 

 50 years the thinnings may be heavier. 



16. SCOTCH PiNE = Pmws sylvestris (L.). 

 a. Utility. 



The timber is light, average specific gravity, air-dried, 

 = *52, soft, but somewhat harder than that of Spruce or 

 Silver Fir ; durable if impregnated with turpentine and 

 not grown too quickly, more durable than that of Spruce 

 and Silver Fir. The value of the timber depends much on 

 the locality where it has been grown, the treatment of 

 the woods, and the age of the trees ; the timber of 

 slow-grown old trees, if sound, is far superior to that of 

 fast-grown or young trees. It is used for a great 

 variety of purposes in the shape of boards, planks, and 

 scantling, for railway sleepers and mining props. It is 

 imported into Britain as red Baltic pine. A fair fuel. 

 It yields turpentine. From the needles an aromatic 

 oil is prepared. 



b. Distribution. 



It is found in Europe between latitude 37 and 70, 

 also in Asia. Its centre of distribution are the coun- 

 tries around the Baltic and German Ocean. Indi- 

 genous in Great Britain and Ireland. It is eminently 



