854 W. A. Norton—Force of Effective Molecular Action. 
as a standard of comparison ; then the ratio which the coefficient — 
of elasticity of any other material bears to that of wrought iron, 
‘ . i 
will make known the value of its molecular ratio a (fig. 1) at 
Some eee n=number of atoms (ultimate mole- 
cules) in unit of length =%/N; KH= coefficient of elasticity; 
T'=tenacity ; f=intensity of effective attraction between two 
contiguous molecules at the neutral distance, developed by an 
increment of distance, equal to ;47. This, in fig. 1, is repre- 
sented by the ordinate 2s corresponding to the small displace- 
ment a2. 4=max. ordinate of the molecular curve. ¢, ¢, an 
ce” are constants. 
of volume= 
2 
ve 
E=c—=<0fn. Tae! Fr’. 
n 
r 
7576, its value is 0°05. Its maximum value is ae and ob- 
tains when /=o, in which case k=4-934, and the molecular 
curve falls entirely below the axis x. / is expressed in te 
of ao or p, considered as unity (see page 346). For the more 
