CHAPTER V. 



ON THE DEFECTS IN TREES (Continued}. 



THE next important defect is the star-shake (Fig. n). 

 This is found in many varieties of timber, and occurs in 

 trees of all ages and conditions of growth. It consists 

 of clefts radiating from the centre, or pith, which often 

 extend far towards and even in bad cases touch the 



circumference of the 

 tree, rendering it al- 

 most valueless for con- 

 version into board and 

 small scantlings. 



The clefts or lines 

 forming the star are 

 generally only slightly 

 open, and can scarcely 

 be seen in a fresh-cut 

 tree, there being no 

 decay of lignine about 

 them. They are, how- 

 ever, very plainly perceptible when the wood is moder- 

 ately seasoned, by the matter forming the two sides of 

 the shake having become somewhat darker in colour and 

 more horny in texture by exposure to the air. 



As before stated, in bad cases the points touch the 

 circumference of the tree ; they even occasionally bulge 

 there, forming a longitudinal rib, varying in length from 



FIG. II. 



