Cryolite Films on Glass Surfaces

Abstract

MANY years ago Mr. Dennis Taylor patented the tarnishing of optical surfaces for the purpose of increasing the amount of light transmitted. To-day, cryolite treatment of surfaces has become a routine operation. The common explanation of the phenomenon is that: (1) equal portions of light are reflected back from the outer and inner surfaces of the film; (2) the phases of these portions are such that they interfere with and neutralize one another so far as visual reflection is concerned; (3) the cryolite film must have a definite thickness.