438 THE POPULAR SCIENCE MONTHLY. 



between 21 and 30, we who are not color-blind could form a clear con- 

 ception of its appearance to color-blind persons, and appreciate how 

 impossible it must be for them to conceal their defects under the inves- 

 tigation of the color-stick. Rose, being composed of red and blue in 

 equal quantities, appears as a tint of blue to the red-blind, and green 

 must look to them gray. 



It has not been the duty of the writer to investigate cases of acci- 

 dent which might have been caused by defects of sight, but he has 

 been assured by officials that a solution will hereafter be found in 

 them for those hitherto insoluble mysteries where men, otherwise 

 credible, have so flatly contradicted themselves and the circumstances 

 of the case. By one prominent ofiicer he was told that, being upon a 

 train at night, delayed by some slight accident, he himself took a red 

 lantern, and, going a proper distance back, placed himself on the track 

 in the way of an on-coming train, but, finding his light not observed 

 he was compelled to dash it into the cab to attract the engineer's at- 

 tention, and arrest him in his progress to a collision. Upon the exami- 

 nation of another engineer, his superior officer being present and con- 

 vinced of his marked color-blindness remarked that, but a short time 

 before, the man had run into the rear of a train properly protected by 

 a red light in the hands of a brakeman some distance in the rear, that 

 the most careful investigation had resulted only in the suspension of 

 the brakeman for not having gone far enough back, but that he was 

 now satisfied that the color-blindness of the engineer had been the real 

 cause of the accident. Some slight or minor accidents recently led to 

 the discovery that another engineer had by some oversight not been 

 tested in his division, and this led to his examination and detection 

 there, and to his conviction by the writer as a color-blind. Still another 

 case now presents itself. An engineer some time ago ran over and 

 killed a brakeman, holding a danger-signal on the track in front of his 

 engine, and no satisfactory explanation could then be given ; but the 

 division examiner predicted that he would probably be found color- 

 blind, and on his examination this proved to be the case. 



As a fact it may be safely assumed, in the various emergencies of a 

 railway service, by day and by night, the year round, that, if an acci- 

 dent could occur from such and such contingencies, it will be but a 

 matter of time when it will become a verity. 



In a recent popular article on " Control of Vision," Dr. Jeffries, 

 who has done more than any one in this country to call attention to 

 its necessity, laments the entire failure in Connecticut, and the par- 

 tial failure in Massachusetts, to obtain efficient legislation to compel 

 railroads to expel their deficient men. He tells us of the like con- 

 dition of things in England ; and finally adds that the Pennsylvania 

 Railway alone has availed itself of scientific advice. Perhaps if the 

 system adopted by it had then been described and urged as most in 

 keeping with our institutions, we might hope to see all the roads in 



