18, 5 Valencia: Commercial Philippine Timbers 509 
E = Modulus of elasticity, pounds per square inch. 
EL= Fiber stress at elastic limit, pounds per square inch. 
J = Greatest calculated longitudinal shear, pounds per square inch. 
K = 27.7 where weight is in pounds, and 0.061 where weight is in 
grams. 
MR= Modulus of rupture, pounds per square inch. 
P = Maximum load, pounds. 
P’ = Load at elastic limit, pounds. 
S = Dry specific gravity. 
W = Weight of specimen, pounds. 
A = Total deflection or compression at elastic limit, inches. 
b = Width, inches. 
d = Distance between centers of collars, inches. 
h = Height, inches. 
1 = Span, inches (compression, 1=length). 
BENDING 
Load applied Uniformly distri- Load applied at 
at center. buted load. third points. 
j_0.75xP j_0-15XP ja Pxh_. 
~ bxXh at a OEP 
tO Sr x 0.75 x PX] lx (P+0.75 W) 
MR= bx<h 2 . MR= Sh? 2 . MR= bxh 2 . 
cers 0.75 «x Px] lx (P’+0.75 W) 
EL= =. oe : _ 
bxh? er ee bxh? 
oh P’x12 P’x15 pete XE 
47 bxh?x A’ 
=axcbxh*xd’ E=64xbxh*xD" 
COMPRESSION PARALLEL TO GRAIN 
P = el ea anaes @ 
/_ EL=;- . oS Ass 
COMPRESSION PERPENDICULAR TO GRAIN 
P’ 
EL=,. 
SHEARING PARALLEL TO GRAIN 
P. 
Shear=—. 
A 
SPECIFIC GRAVITY 
Wet weight « K 
(1 + per cent ne) < volume in cubic inches 
