86 PROPERTIES OF WOOD. 



therefore produces the most underwood. Unfortunately the 

 'time required is longer than the usual rotations, and trees 

 grown in crowded crops must be utilised early owing to low 

 increment and disease (red-rot). 



The influence of soil on the quality of wood is such that 

 good soils produce woody zones that are broad and irregular, 

 and consequently coarse-grained wood. The worst soil, or 

 soil that is deficient in certain qualities, such as sand or peat, 

 produce slowly grown crops, but wood that is finely grained. 



In damp, cool climates, i.e., maritime, northern or 

 alpine climates, and on northern aspects, trees grow slowly 

 in girth, and their wood is uniform in texture and finely 

 grained. Norwegian, Swedish and North Eussian wood is 

 renowned for its fine grain, while the famous resonant spruce- 



io 1 . 42. Wood of a tree 'that has stood in a free position both when 

 young and old. 



wood from mountains is the ideal of fineness of grain. Inter- 

 ference with the fineness of grain in wood, owing to knots, 

 twisted "fibre, etc., belong to the section on the defects of wood 

 (p. 124). * 



2. Fissibility. 



The property of wood owing to which it may be split with 

 wedges, etc., is termed fissibility, and depends chiefly on the 

 direction in which the force acts. Fissibility is greatest 

 when the splitting implement, e.g., an axe, acts longitudinally 

 and radially on a transverse section of the wood. AVood is 

 less fissile when the axe strikes the tangential section along 

 a radius, still less fissile when the wood is to be split along 

 Uie iumual /ones, and this is easier on the trnnsverse section 

 than when the axe strikes on the radial section. Wood cannot 

 be split if the force acts perpendicularly to the direction of its 



* [ Types of I lie wood of oak, larch, and spruce of various kinds of 'jmiii a re p von 

 in the frontispiece, the last taken from I'.oppe's "Technologic Forest iere." Tr.j 



