Jay Holben The next in line on our examination of lighting fixtures is the PAR, which is an acronym for Parabolic Aluminum Reflector. The classic PAR is a reflector and lamp all in one. It is a sealed ...

PRIOR to the year 1822, the optical apparatus used in the best equipped lighthouses was silver-plated parabolic reflectors, having apertures, twenty-one inches for fixed, and twenty-five inches for ...

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A light rigid structure (of aluminum or other material) which reflects sound to a focus at which a MICROPHONE is placed. This focussing effect is very strong with WAVELENGTHs less than the aperture of ...