Page:Timber and Timber Trees, Native and Foreign.djvu/50

 CHAPTER V.

ON THE DEFECTS IN TREES—(Continued).

next important defect is the star-shake (Fig. 11). 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 almost valueless for conversion 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, however, very plainly perceptible when the wood is moderately 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