98 FORESTRY 



CHAPTER VII 

 FOREST UTILISATION 



UNDER Forest Utilisation are considered the harvesting, con- 

 version, and disposal of wood, and the transport of forest 

 products, so far as these actions lie within the sphere of the 

 forester's business. In all of the above departments, the 

 systems employed tend to change greatly according to time 

 and place ; that is to say, the uses or modes of preparation 

 of wood in one country may be different in another, or even 

 within the same country ; and the same remark applies to 

 the period or date of utilisation. Frequently forest products 

 receive partial conversion before passing out of the hands 

 of the forest owner, and this forms a special or independent 

 branch of the subject. 



The Properties of Timber 



Weight. The weight of wood depends upon species, age, 

 portion of stem being dealt with, degree of moistness, internal 

 form or structure, and conditions under which the timber has 

 been grown. 



A division of our timber trees into three groups, according 

 to the weight of their timbers when dried, is as follows : 



Light woods, having a specific gravity of 0-55 and less : 

 Scots Pine, Weymouth Pine, Silver Fir, Spruce, Lime, 

 Poplar, Alder. 



Moderately heavy, having a specific gravity of 0-56 to 

 0-70 : Larch, Birch, Sycamore, Sweet Chestnut, Elm, 

 Beech. 



Heavy, having a specific gravity over 0-70 : Acacia, 

 Hornbeam, Ash, Oak. 



The lower portions of a stem are generally heavier than 



