v.] CULl-SHAKE. 31 
about a foot to two or three yards. We have thus ex- 
ternal 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. 
FIG. I2a. FIG, 128, 
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 @ and 6). This shake, which 
is most frequently met with near the roots of trees, | 
consists of a cavity or separation of two of the con- 
