﻿12 Prof. L. N. G. Filon : Investigation of Stresses 



we have the following approximate expressions 



„ . 2W.„' _,, 8^V„ 3M T8WH, 3M -| , 



2S= 2 -™fW 



7rr J 



Hence, i being the inclination of the nicols, 



(/ sin 2f>y 2 



tan 2z 



ojlini n / 4H o 3irM \ /4Hx 3ttM \ 

 (y cos2c/>)/,-( r + JWPJ+U + 4W^) 



Write for shortness 



4Hi 3M tt _ 

 b*~ + 4Wb*~ q ' 



4H 3M tt 



Then equation (11) may be written 



./v'cos 2<f>' 7 , , A 

 , 2 -21 - ? ft -f yy J, 



(11) 



'// 



f, 2 sin 20' = tan 21^ 



or 



.V 



2sin2(0 / -i) = (y-^sin2i (12) 



This may be expressed more concisely still in the following 

 Fte. 3.— b'>0. 



way. Let C (fig. 3) be the point of loading. Let DEQ be 



