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I HAVE been using a refraction aid that is convenient and helpful. It consists of a battery of lenses that enables the refractionist to go "round the trail case" with ease and speed. It consists of two +0.25 spheres, two -0.25 spheres, and a crossed cylinder, -0.25 sphere [unk] +0.25 cylinder, at the top.
The accompanying photograph is self-explanatory.
This instrument was made under my direction by the Strong-Kennard Company, Rose Bldg., Cleveland 15.