Page:Timber and Timber Trees, Native and Foreign.djvu/51

V.] about a foot to two or three yards. We have thus external evidence of the presence of the star-shake in this extreme case while the tree is yet standing. We can, therefore, from this alone, estimate its value, and prove the correctness of our opinion of it after the tree has been felled. No one, I imagine, experienced in timber-surveying, would, with the bulging rib in view, care to examine either the top or butt end of the log to satisfy himself of the presence of the star-shake; the guide is so absolutely certain that we need not fear to trust to it.

My experience will not enable me to account for the star-shake, and I do not remember to have seen any reasonable explanation given in any work respecting it. I may state, however, that it is more frequent in trees which have been grown upon either a sandy or a rocky soil, than in those which were grown upon loam or stiff clay.

The cup-shake (Figs. 12 a and b). This shake, which is most frequently met with near the roots of trees, consists of a cavity or separation of two of the