174 
MR. L. N. G. FTLON ON THE ELASTIC EQUILIBRIUM OF 
From Diagram I we see at once that a discontinuons cliange in the slope of the 
deformed outer surface of the cylinder occurs at the points 2 = d: c/3, i 2c, 3, 
between wliich the nniform shearing stress is applied. Tleferring to equation (53) 
we see that at those points dujdz changes abruptly by the value — ^S/p, where 
S is the al)rn[)t increase in tlie shear. This residt is exhibited in the curves referred 
to, and we notice that the effect of shear, applied to the outer surface of a cjdinder. 
Diagram 2.—Distortion of the Cross-sections of a Cylinder under Shearing Stress applied to the 
Curved Surface. 
(m'o = r/2 on the scale of the diagram.) 
1, 2, 3, 4, 5, 6, 7, 8, 9, 10 undistorted cross-sections. 
\a, 2a, 3a, ia, 5a, Ga, 7a, 8a, da,, lO'f distorted cross-sections. 
is to depress that part of the surfirce towards which tlie shear is acting. In fact 
the greatest contraction tliroughout the cylinder occurs near the points 2 = d: 3 
and ap})ears due to this effect. 
Near the ends the cylinder ]:)roadens out again, as we shonld expect, though it is 
to he noted that the distorted generators meet the plane ends obliquely, which 
should not be the case if the condition of no stress over the plane ends were 
accurately fidfilled. This we know is not so : there is a system of finite shear over 
the plane ends, as is easily seen on referring to the table of rz on p. 172. This 
