474 SUMMARY OF CURRENT RESEARCHES RELATING TO 
“ "irC mirrors, ... .1 * to. - *■» <■«■“ 9 “■ 
'““he opticl p«ti»» °< *«• Microscope is 
•J5S CilK' «£ piilioos, .Mr combine! fees 
being If in. , f i „„ n0 se-T)iece an equi-convex lens 
There is at the upper end of ^“8 t P uot 0 f the eye-piece, hut 
of 54 ,- in. focus ; this must be ,®°“ s , k P en g 0 f the objectives, for it 
of the objective. In reahty it is the ob j ec tives, it is only 
is common to them all; so that, inch g g tica J n y speaking, is an 
the front lens that is , < ? ia ”§ e 4' 0 f Martin. The same optical 
improvement, is probably th< « mT* Options copied one 
arrangement was employed by Adams m I 
