270 THE UTILISATION OF WOODLAND PRODUCE. 



sawn, timber is lighter in colour than when seasoned and long 

 exposed to the air ; and steaming always darkens its natural 

 colour. Woods used for ornamental purposes, such as furniture, 

 wainscotting, &c., are chiefly selected on account of their colour, 

 texture, and marking ; and the coarser the grain of the wood, 

 the more the texture and the marking are displayed (as in Oak, 

 Elm, and Ash), while the greatest variety of marking is shown 

 on a radial section fully exposing the medullary rays (e.g., the 

 " flowering " of Oak). But the coarser the grain, the better a 

 wood takes a polish, as the material used settles easily in the 

 pores. Forked growth and abnormal "burr" excrescences in- 

 crease the value of timber for ornamental purposes, though 

 depreciating it for building and construction. 



The usual colour of sound wood is as follows : 



IV. The Physical Properties of Timber, upon which its 

 mechanical properties directly depend, and which are therefore 

 of far more importance than its outward appearance, are (1) its 

 density and weight, (2) the amount of water it contains, or the 

 extent to which it is seasoned, (3) its relation towards drought 

 and moisture, as to shrinking, cracking, splitting, warping and 



