GENERAL QUALITIES OF TIMBER, 183 



firm and durable. An oak whicli stands alone on a 

 hill side, exposed to the variable weather of Britain, 

 will, as timber, outlast two from the thick forests of 

 Germany, or three from North America, where the 

 summer is intensely hot, and without a cloud for 

 many weeks together. 



Trees which are to be used as timber should be 

 felled in the early part of the winter when the sap is 

 at rest ; because, when the sap is in motion, the 

 trees are apt to bleed, by which the durability of the 

 timber is diminished. This applies to pines as well 

 as to deciduous trees ; for though they and other 

 evergreens retain their leaves during the winter 

 months, they do not vegetate at that season. On 

 account of the value of the bark, however, which 

 cannot well be removed from winter-felled trees, 

 there is a great temptation to fell oaks in the early 

 part of the summer. In coppices, or hags, where 

 the bark is the principal object, and the wood is to be 

 used for charcoal or for common purposes, there is 

 of course no harm in cutting down during the season 

 of vegetation ; but a summer-felled oak ought never 

 to be introduced into a ship, or hito the timbers of a 

 valuable permanent building'. 



Oak grown on damp situations decays much 

 sooner than that which grows on dry, and the decay 

 is from the outside gradually to the centre. This, 

 however, is to be understood of timber which has 

 been felled before beginning to decay ; for if decay 

 be begun, the timber rots first at the centre. 



Oak is best seasoned in water, or rather in water 

 and in air alternately, taking care not to expose it so 

 to the sun during the dryings as that it shall champ 

 and split. A large beam of oak ought to so.ik for 

 at least twelve months, but half that time will do for 

 planks. It is often the practice to season planks by 

 boiling and steaming ; and when they have to be 



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