International Library of Technology · Scranton, International Textbook Co. · leaf 380
long distances. Asmall concave reflect-or is usually placed, asshown at r, to throw the rays of the arc that would ordi-narily pass outwards back towards the main reflector.A parabolic ground-glass silvered mirror is used in the United States Navy, but forordinary commercial workthe Mangin mirror… … Fig. 8.
Electrical engineering
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