10 



BULLETIN 67, U. S. DEPARTMENT OF AGRICULTURE. 



of greatest deflection was most noticeable in the poles having a ten- 

 dency toward longitudmal shear. The effect of knots was in evi- 

 dence only as locaUzmg the compression \^Tinkles and occasionally 



'^ 



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. 



