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Show COLOR-BLINDNESS MISNOMER, RAILROAD OCULIST ASSERTS Faultily Tinted Lenses Are Blamed by Dr. G. B. Pfoutz of Oregon Short Line for Engine-men's Engine-men's Failing to Pass Tests. THE term 'color-blindness' is a misnomer. Some men are color defective, but to be color-blind a man would have to be totally blind. A very small percentage of men are at all defective in their color sense, not much more than 2 per cent." This is the statement of Dr. G. B. Pfoutz, Inspector and examining oculist of the Oregon Short Line railroad, in speaking of the danger of color-blindness among railroad men. J "Engine drivers and motormen who formerly failed to distinguish the hues of colored lights were not always color-blind," he said. "The error was formerly caused in many cases by faults in the material, used to tint lenses. ' "Recent investigations and tests show : that not only the eyes must be perfect in their color perception, but that the utmost care must be taken by the chemist in advising ad-vising the kind of material for coloring glass. "Red as a danger signal and green for a clear track are firmly established in railroading. What would happen if the same signal appeared sometimes red and sometimes green to the man in the cab? But for the safeguards of chemistry, this might occur frequently and. In fact, it has happened enough in the past to cause railroad executives and manufacturers to be unusually careful about the composition composi-tion and coloring of the lenses of the lanterns lan-terns employed in signaling. "An engine driver who had been running run-ning on a certain railroad for years was suspected of failing vision, and was sent to the office of the traffic superintendent to examine and identify a mixed skein of colored yarns. He was deeply offended that anyone should ask him to, undergo such a test. ' Lenses at Fault. ' T am not an old woman, he exclaimed. 'Meet me in the yards tonight and I will pick out the lights for you, all right.' "Three lights were placed on an engine and the veteran of the lever was asked their color. " 'They're red,' he answered. "The locomotive was moved further away and the driver again identified the lights as red. "When the distance was further increased, in-creased, he said: 'Two red, with a green between them.' "The test was repeated with the same perplexing result. "This was the situation: The man was growing weak in color perception, especially es-pecially as far as red was converned. It -was not all his fault, for it was found that there were differences in the red glass discs of the lanterns, as revealed by analysis. Glass transmits those wave lengths which it cannot absorb. In this instance the center red glass had permitted per-mitted green to pass with the red and while all eyes would not have nerceived it, others, with peculiar characteristics would have done so. The red discs employed em-ployed were made of copper ruby glass. "Glass that is unquestionably red owes its true transmission of red rays to the presence of a waste material, a by-product of copper refining, for which chemistrv had been seeking a use selenium. If selenium ruby glass be compared with other ruby glass by means of a-spectro-scope, it Is seen that those colors beyond the red, and toward the blue end of the spectrum fall to pass it, while various wave lengths slip through other less reliable re-liable vitreous material. Tests Standardized. "This test has become starf&irdized and a spectroscope permits onlv glass of the proper qualities to get into the railway signals. "If a man sees red now, and now green, there need be no question, if selenium is used in the color glass, as to his responsibility. respon-sibility. "Every employee of every railroad in the United States, connected with the operation of signals, is perfectly free from color defection, and is periodically examined exam-ined to insure that his sense of color has not failed," Dr. Pfoutz continued. "Because "Be-cause of the standardization of the lenses used in railroad signalling and the periodical peri-odical inspections, accidents from failure to perceive colors are now almost unknown In railroading. The last case I remember of a color accident occurred in the eighties. 'jAn old engineer who had been on the road for years, came Into mv office and said: 'Doctor, I'm either blind, or my fireman Is raving mad, but I believe I'm blind.' " 'What's the trouble, Bill?' I asked. Vision Is Defective. " 'Well, sir, the other dav when we were 'sailing along out on the prairie thp fireman yelled to me that there was a red cow on the track. I looked out and I couldn't see a darned thing. So I kept right on. A second later there were a . couple of hangs and a sizzle, and after the smoke cleared away 1 discovered' we were derailed, de-railed, and the carcass of a cow was scattered all over the scenery. What there was left of that cow was red. But why in the Sam Hill didn't I see that cow on the track?' "I took the man Into the examination room and gave him the color test, which In those davs was just coming Into use. I He was stone blind to red. He couldn't ' tell it from any other color, and couldrr't I distinguish it at all. When the results of the examination were told him he quit the cab and went into the sho,,. He wouldn't trust himself "with the lives of passengers. "The explanation of this was that the man's eyes had been gradually losing their color perception, perhaps through the use of tobacco, which affects some men in that way. The dark red soil over which he was traveling' at the time and the wavering bushes with their frequent touches of red, had dimmed' this man's eyes to red. The color of the cow had so merged into that of the ground that his falling perception could not notice It. His assistant, whose eyes were quite normal, nor-mal, could easily distinguish the cow. "But such incidents as these are now eliminated by the periodical inspection and the better quality glass lenses. Color defection de-fection among railroad employees has siru- ply ceased to exist." |