indicated on the inside scale (red) mav be “near sighted” in one diameter and “ far of the disk, B, which is revolved in the opposite direc- sighted ” in another. As to muscle troubles, few people tion from what it is in testing for hypermetropia. know that prisms are prescribed mounted in… … opera glass, and Fig. 4 shows the | sign was prepared by Charles E. Barber, of the United effect on the light beam of tilting| States Mint, so that the medal as issued will be the the negative or eye lens. In the]joint work of Messrs. St. Gaudens and Barber, the mitted to the tests in vogue…
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