10 
BULLETIN 67, U. S. DEPARTMENT OF AGRICULTURE. 
of greatest deflection was most noticeable in the poles having a ten- 
dency toward longitudinal shear. The effect of knots was in evi- 
dence only as localizing the compression wrinkles and occasionally 
si 
at the starting point of a tension crack. In the cedar poles many 
shallow ax cuts had been made when the bark was removed, and 
tension failures always took advantage of these breaks in the fibers. 
