PAPERS OX CHEMISTRY AXD PHYSICS 



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F'j.I- /" ,s' 



angle that the mirror is turned. The magnification is 

 increased by increasing the number of reflections and by 

 turning both mirrors in opposite sense. It is evident 

 that in Figure I if the short mirror had turned an equal 

 amount in the opposite sense to the long mirror, we 

 would have increased our magnification. 



n. LIMITS OF THE EAXGE OF *^THE AXGLEOMETEB" 



The nearer to the perpendicular the incident ray is 

 brought, the greater the number of reflections, and the 

 greater the magnification. But on account of the ab- 

 sorption of the mirror with each reflection, we are limited 

 in the number of reflections. With a mii*ror of 95 ^t re- 

 flective power, and allowing 50 reflections, there would 

 about 10^ of the light get through as the emergent ray. 

 This is not an impossibility, for with a very intense 

 source and an emerging ray one-tenth the intensity as 



