. Electric railway journal . business holds no place for a manwho is color blind, color ignorant, or confused whenhe sees two colors at the same time. The second color test is made with the Williamsrailroad test lantern, which is shown in one of theaccompanying illustrations. Every railroad company,regardless of its size, should use one of these lanternsin making examinations. As railroad signal colors,red and green, are those usually confused by color-blind persons, tests for color sense are particularlyimportant. People may be color blind for green or forred, or for both. The lantern used by
. Electric railway journal . business holds no place for a manwho is color blind, color ignorant, or confused whenhe sees two colors at the same time. The second color test is made with the Williamsrailroad test lantern, which is shown in one of theaccompanying illustrations. Every railroad company,regardless of its size, should use one of these lanternsin making examinations. As railroad signal colors,red and green, are those usually confused by color-blind persons, tests for color sense are particularlyimportant. People may be color blind for green or forred, or for both. The lantern used by the elevatedrailroads is fitted with a revolving disk containingthirteen small lenses. These lenses are of variousshades of red, green, blue, white and amber, and maybe revolved before two apertures. On another revolv-ing disk are small London glasses smoked to variousdegrees. When these smoked glasses are placed overthe clear colors, they make the light appear like thatof a dirty or smoky signal lamp. Two levers operating. CHICAGO ELEVATED MEDICAL EXAMINATIONS—WILLIAMSLANTERN AND CHART RACK small disks of frosted glass are used to make the lightresemble that of signal lamps in a fog or a rain. Anindication like that of a smoky signal lamp on a foggynight may also be obtained. The Williams lamp also has three sizes of dia-phragms or openings—large, medium and small. Whenthese are placed over the colors and the size of theapertures is changed, the appearance of a regulationswitch lamp on a dark night at distance of y2, 1 and2 miles may be obtained. During the examination thelantern is placed in front of a dark background andall other light excluded. The applicant is seated 20ft. from the lantern and each eye is tested is requested to call the colors quickly and correctly,and any confusion merits rejection. Another test often used is to place two red signallanterns, two green ones and a white one in a dark roomand request the applicant to pick out the colors ca
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