10 
BULLETIN 77, U. S. DEPARTMENT OF AGRICULTURE. 
increased the strength and stiffness of the wood but decreased its 
toughness. 
INCH-POUNDS PER CUBIC INCH 
Fig-. 4.— Relation of unit strength of 16-foot round beams to condition; based on average values of the 
three sizes tested. 
In comparing fire-killed and green material, the grade of both, in 
regard to ordinary defects, should be taken into consideration. The 
