18 
BULLETIN 1436, U. S. DEPARTMENT OF AGRICULTURE 
others saw off slabs in order to make flitches from which they cut 
the blocks. Blocks are usually wider than thick. They shrink with 
less distortion (warping, cupping, twisting, and diamonding) if 
SHUTTLE BLOCKS SAWED THIS WAY WILL 
NOT DISTORT GREATLY IN SHRINKING 
SHUTTLE BLOCKS SAWED THIS WAY WILL 
DISTORT CONSIDERABLY IN SHRINKING 
Fig. 11. — Proper and improper methods of sawing out shuttle blocks 
cut so that the top and bottom are parallel to the growth rings as 
seen on an end section (figs. 11 and 12). They are therefore much 
to be preferred to blocks with the growth rings on an end section at 
END OF PROPERLY SAWN BLOCK 
OREEN FROM THE SAW 
GROWTH RINGS PARALLEL TO 
TOP AND BOTTOM OF BLOCK 
SAME SHUTTLE BLOCK AIR-DRY 
(SMALLER IN SIZE AND WARPED 
IN DIRECTION OPPOSITE TO THE 
CURVE OF THE GROWTH RINGS) 
Fig. 12. — A properly sawn shuttle block before and after drying 
an angle to the top and bottom. The block cut at an angle distorts 
more than the block cut parallel because the wood in a tree shrinks 
more along a line drawn tangent to the annual rings than it does 
along a line drawn perpendicular to them. (Fig. 11.) There is 
