9G TECHNICAL PIIOPEHTIES OF WOOD, 



regions, cold aspects and density of growth during youth are 

 advisable, and their crowns should be isolated only when their 

 height-growth is nearly completed. By following such rules 

 durable timber will be produced. 



Decay of Avood owing to fungi can arise only when the wood 

 contains sap or moisture ; direct means for increasing the 

 durability of timber must, therefore, consist in keeping it as dry 

 as possible from the time of felling until it is utilized. 



Drying timber in the forest is effected by converting the 

 trees into beams, scantling and firewood, and exposing the 

 pieces in airy places, after raising them above the ground. 

 Large timber cannot evidently be much reduced in size ; but 

 drj'ing may be expedited by barking the logs and dividing them 

 into halves and shorter pieces. In extraordinary cases, trees 

 may be dried by barking or girdling them before they are felled, 

 or by felling them when in full leaf and converting them after 

 they are fairly dry. Wood never becomes thoroughly dry in 

 the forest, and it is the wood-merchant and not the forester who 

 has to see to the thorough drying of timber. 



Special care must be taken of wood which has been killed 

 during the growing-season by insects or fire, or which has 

 become coated with blue mould. Such wood should be prepared, 

 barked and converted at once, if it is to be kept sound. 



A high grade of dryness may be secured, in exceptional cases, 

 if a tree is girdled as it stands, or barked up to its crown and 

 left standing till all the moisture in the trunk has been trans- 

 pired by the foliage. Oaks are sometimes barked in this way in 

 the spring, when the bark is wanted for tanning, and then left 

 standing till the following winter.* Such wood is characterized 

 by exceptional durability, and is in great demand by wheel- 

 wrights. Trees intended for use in the Russian navy are barked 

 during the growing-season, and only felled twelve months after, 

 and in order to prevent cracking, the bark is separated from the 

 tree in strips 10 to 12 inches broad, wliicli are carefully left 

 hanging from below the crown of the tree, and then titd round 

 the stem with withes, f 



* [This is done in the Forest of Dean. — Tu.] 



t [In Burma, all teak trees marked for felling are girdled, and may not then 

 be felled for two years. — Tu.] 



