IV.]
HEART-SHAKE.
29
very scant, or perhaps to trees unequally balanced in their branches, if grown in the open. There is something like evidence of this twisting in the spiral turns of grain noticed in many trees.[1] The heart-shakes are equally disadvantageous, if, indeed, they are not more
FIG. 9.
so, when they cross each other at the pith, and open to the full diameter of the tree, splitting it into four segments. This form of the defect is very conspicuous in the Green-heart timber (Fig. 10).
FIG. 10.
- ↑ This spiral growth is common in the Turkey Box tree; it is also frequently seen in the Fir and Pine species, and occasionally in other woods.
