The Durability and Preservation of Woods 241 



been much discussion on the subject. This importance 

 has probably been greatly exaggerated. Since the pres- 

 ence of moisture is necessary to the growth of fungi, the 

 time when the least moisture is in the trees should naturally 

 be chosen, the autumn or winter. This time of cutting 

 has the further advantage of having the last season's 

 layer of wood fully lignified and . thus more resistant of 

 decay. The chief objection is the difficulty of peeling 

 the bark from logs cut at this time. On the other hand, 

 logs cut in the spring or early summer peel readily and 

 season quickly in the ensuing hot weather. The only 

 difficulty is that some woods, especially oak, will season 

 too rapidly and consequently check badly. These cracks 

 are very injurious to the logs and form good openings for 

 the attack of the fungi, which are especially numerous at 

 this season. 



Fall or winter is a good time for the cutting of all species ; 

 it is the best time for oaks and all other woods that check 

 badly in seasoning. Other non-checking species may be 

 cut in the spring; they are easily peeled and advantage 

 may be taken of the rapid summer seasoning. 



Naturally durable woods 



Some woods are naturally more durable than others. 

 Chestnut or cedar will last in the-ground for years, while 

 cottonwood or birch will often rot within nine months. 

 For this reason there has, in the past, been a tremendous 

 demand for the so-called durable woods for fence posts, 

 railroad ties, telegraph and telephone poles, and so on. 

 The supply of white oak, white and red cedar, chestnut, 

 red elm, black ash, locust, coffee tree, cypress, tamarack, 



