We have seen how a log in drying cracks along the radial lines (page 31), thus showing the natural lines of cleavage or separation in the direction of the medullary rays, that is, radiating from the centre. From this we see that the wood will, of course, split most easily and smoothly on the radial lines. Like all wood-choppers you can often make practical use of this fact in splitting wood with a knife or chisel, or in splitting fuel with an axe. The next easiest way to split wood is as nearly as may be on the line of the annual rings, or tangential to the line of the medullary rays, in the same direction as when the layers separate in forming " cup shakes " (see Appendix). This way is sometimes easier than to rive a stout log through the centre.