130 



PROPERTIES OF WOOD, 



A slight waviness of fibre is very common and affects the 

 quality of the wood but slightly. The shorter and more 

 curved the bends of the fibres, the more the utility of the 

 wood for cleaving is impaired. Its value for planks is 

 increased by the beauty of its structure, which may form 

 highly ornamental wood, as when sawn into planks alternate 

 layers of fibres run in different directions and reflect light 



differently. The 

 ripples may be in 

 the tangential sec- 

 tion of the wood, as 

 in Fig. 47, or in the 

 radial section, when 

 the wood is termed 

 commercially 

 "hazel," as "hazel- 

 spruce " or hazel- 

 oak. On the upper 

 side of a junction of 

 a branch with the 

 stem, or near the 

 roots, the wood is 

 always wavy, this 

 being more marked 

 in broadleaved 

 trees. [The ripples 

 of fibres are normal 

 in satin-wood 

 (Kanthoxylum from 

 the West Indies and 

 Cldoroxylon Sicic- 

 tcnia from Ceylon), 



Fig. 47. Ash-wood with wavy fibres. Curl-wood. 



so that the wood on longitudinal sections has always alternate 

 bands of brighter or duller lustre, according to the direction 

 in which the fibres are cut. The medullary rays also undu- 

 late. This beautiful wood is extensively used for the backs of 

 brushes. Tr.] 



Mottled wood results from the shoots from dormant buds, 

 which remain alive for years at the level of the outer bark ; 



