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Show THE OLD COAL OIL LAMP. What is the best light for the eyes, a question often asked, is answered by a writer in a London paper, and the article is worthy the attention of all who do much work at night which calls for a strain on the eye3. "I do a great deal of reading and writing by electric light," writes Eustace Miles. "The other day an electrical specialist told me that a certain kind of electric light was very bad for the eyes, because it was deficient in the red and yellow rays, and because it had the ultra-violet rays to excess. In these days, when so marfy children wear spectacles more, perhaps, in Germany than in England Eng-land the matter becomes one of national importance. "It seems to me that too little distinction is made between light that is economical in proportion to its brightness and cheerfulness and light that is comparatively uninjurious." A well-known scientist explained recently that of all artificial illuminants at present in use, the acetylene flame most nearly approached ap-proached to the character of daylight. "Both oil lamp and candle light are good, too," he said, "because "be-cause of their yellow character, which is about the least harmful color to the eyes. "Daylight is, of course, the ideal. Daylight is a mixture of all colors, and, as far as the eyes are concerned, the greenish-yellow rays predominate. Itis the invisible and ultra-violet rays that are bo harmful, and of these in daylight there are not enough to hurt. "Of the various forms of electric light, the violet is the most harmful. The now popular metal filament lamps also contain many of the harmful rays. "But the metal filament lamps could be madeto give a light optically the same as daylight were they made of a properly measured tint of bluish-green glass, preferably frosted. Even as it is, the glass of which they are made absorbs much of the harmful rays." Thirty years ago few persons, comparatively, used eye glasses. Now a big per cent of the people are forced to wear the aids to sight. One reason for the early absence of glasses may have been the lack of knowledge of the benefits to be derived, yet, no doubt, there were not as many people afflicted with defective eyes, and that condition, in part, is to be attributed to the softer light given off by the old coal oil lamps and the candles then in every home. |