= 
ae eee ee: 
ot ing i quantity of snite light i in the 2 Ie aoe 
_ we must follow the method already explained for the reflected 
Tay, mutatis mutandis. The principal section of the analysing rhomb 
being now supposed to be placed in a plane perpendicular to the 
plane of —— = ere light Q’ recede in 1 that plane, 
sail be:. 
QMis 2 cos *o, - bbe: Bi ph paiees 
the pei iS ened light being unity. But,” 
Cot g=cot x spied ae 
eee: es =, and sin? ¢+cos? 9=1, we hae he gunn 
seed We bed of sin? i salicee 58a ihe Hence 
(cot x cos (t—7’))? 
Kael P™ 1+ (cot x cos (1-1)? 
swa'up substituting this for cog? g in the former equation, it 
(cot « cos (i—1’))? 
i ho Rear Te (t—7))? 
