630 ‘PROCEEDINGS OF SECTION H. 
hence (13) becomes 
=p f (- — Ay - Bx + C)ds + 2 | f tee+ 
ft oars 
ray) ae 
tne ales Aah =) 
or Kz = — a Bo 
t A cos @ she f 
al (4 sin f— Boos) +e x ea +D (4) 
EH 
From symmetry si a A 
hence B= 0 
Again since ae = us fe a 
and since the ‘angetial displacement vanishes at A and B, 
and the tangent is fixed in direction at these points 
“ft = aR at A and B. 
giving two equations for Cand D, 
we have w= Pic _ : 
AOU mal A( *) - 
“Dien i - 
hence when y~ = 0 ort we have remembering a = 0 
pea ees 
ei seg I ¢ 
Sift OU AES ow CS 
hence from (4) we have when ~ = O or ll 
2 
Aab = iN eee | : \ Ww sie 
— Fr" : Asin @ pee (e sin p) ¢ + Spr yp 
_ oe 
re A eo) 
FIGLe 
