MECHANICAL PROPERTIES OE WOODS GROWN IN 'UNITED STATES. 25 
Uniformly distributed load: 
0.75 xP 
J = 
MR = 
EL = 
E = 
bxh 
0.75 xPxl 
bxh 2 
0.75xP'Xl 
bxh 2 
P'Xl 3 
6.4xbXh 3 XA 
Any loading: 
M=l/6Fxbxh 2 . 
Where M = moment in inch-pounds either external or internal, 
F = fiber stress for moment M. 
J = 3/2x i y i where J = unit horizontal shear at any 
point and V = total vertical shear at that point. 
COMPRESSION PARALLEL TO GRAIN. 
P 
cs= z 
P' 
EL =X 
F P'xd 
E= AXA 
COMPRESSION PERPENDICULAR TO GRAIN. 
P' 
EL= B 
Shear =-^- 
S = 
SHEAR PARALLEL TO GRAIN. 
SPECIFIC GRAVITY. 
weight X K 
( 1+ % — Ycj?) — ) x volume of piece in cubic inches, 
