Since the above was written, comparative tests were made, with most interesting results, of different makes of roundels used in signal work. It was found that the difference in intensity of color of a signal was due in a great many cases, not to the care taken of the lamp, etc., but to the poor quality of the roundels themselves, there being a difference of 77 per cent in the amount of the original illumination transmitted by the poorest and best; spectroscopically, the difference between 17.4 per cent and 73.1 per cent of pure red light transmitted

representative medical societies of the United States i. e., Section on Ophthalmology of the American Medical Association, the House of Delegates of the American Medical Association, the American Ophthalmological Society, and the American Academy of Railway Surgeons. There is a fifth report, which I have been unable to obtain so far, adopted by the American Railway Association.

These reports are all the result of careful and painstaking work, by men who have devoted a great deal of time to the subject. Dr. William

Fig. 10. Block signal with bad foreground. Thomson was the first in the United States to inaugurate a system of practical examination of railway employes, and in 1881 this was adopted by the Pennsylvania Railroad Company. All here are familiar with the good work done by Dr. Frank Allport and Dr. Charles H. Williams.

Many roads are using a set of rules for the

With +1.00 D. before each eye my vision was reduced to 20/40 (6/XII) with the Shellen test type with which I could make out dayposition signals at about 2,800 feet, night signals at about 3,000 feet. Plus 1.50 gave me 20/80 (6/XXIV) vision. With these I could not make out a signal until within 200 to 500 feet.

MEDICAL REPORTS REGARDING THE STANDARD OF

VISION.

There are at present four reports as to the standard of vision and hearing required by

some one of these reports, and it is my opinion that if what we wish to arrive at is uniformity in examinations among the various railroads, the medical organizations must have a uniform report. These reports vary but little in the essential features, and any one could well be adopted by all.

Regarding the sections of the four reports, all agree as to the necessity of examination for vision and hearing.

In Section 2 there is a slight bone of contention, and while it must be admitted that examinations by ophthalmic surgeons would be

more scientific and more nearly correct, it has been conclusively shown that examinations carried out under the instruction of an ophthalmic surgeon, by men selected by the company, who refer doubtful cases to such surgeon, have resulted in perfect satisfaction to all concerned.

The reports all agree as to the standard of test types used. A word may be said here regarding uniformity of illumination of test type, inasmuch as uniformity is the watchword. We all know what a variation there is in the intensity of illumination of test charts, and this results in a very great difference in the grade

the rule requires 20/20, the object being that when a man first began his work as engineman or fireman you wanted to begin with a man who had normal vision. It seems to me that it is hardly fair as it works out. If he has 20/30 on re-examination you will allow him to continue to run as fireman, and if he has 20/30 on reexamination you will allow him to continue to work as engineman; then, why not allow him. to be transferred from one side of the cab to the other with the same amount of vision, 20/30?

Fig. 11. Block signal with bad background. of visual acuity obtained by different examiners. A transillumined or self-luminous test cabinet is the only means of overcoming this difficulty.

The section referring to the minimum requirements for acuteness of vision is the most important clause, and all the reports agree that 20/20 (6/VI) vision in each eye without glasses shall be required for entrance into service or promotion.

The standard of 20/20 (6/VI) V. for entrance into service for Class "A" is the least that should be required; but when it comes to promotion in service, there should be some concession made, for firemen who have stoked from five to eight years show, as a rule, some loss of vision, especially in the left eye, which improves, according to the records, after the change in environment. Dr. Williams says:

A fireman who has worked for some six years satisfactorily as fireman comes up for promotion to engineer. He has only 20/30 vision;

Fig. 12. Interlocking block signal with bad
background.

The House of Delegates' report and that of the American Ophthalmological Society require for re-examination of those in the service, "20/30 with both eyes open, without glasses," with the additional requirement that "each eye should be tested separately and the vision of each noted." Under this ruling a man with one blind eve could be retained in service, and Dr. Williams brings the following argument forward in support of what he acknowledges to be a fact:

This rule allows a man to continue running who has 20/30 of normal vision in one eye and little or none in the other. The fact of such defect is brought to the notice of the operating officer in the report of the examination, and a man with this defect would naturally be assigned to less trying runs than would be given

to those with perfect sight. A standard has sometimes been recommended which provides that in this class a man must have vision of 20/30, or better, in one eye, and .20/40, or better, in the other in order to be passed as satisfactory. Suppose a man had 20/20, or normal vision, in one eye, and 20/50 in the other. This rule would reject him, which seems unfair. In such a case the man, for all practical purposes, uses only the visual impressions which he gets from his good eye, and it makes little difference to him in his work whether the poor eye has a vision of 20/50, or 20/70, or 20/40. The work he is able to do is measured by the capacity of the better eye, and he becomes so accustomed to the monocular vision

in one eye, 20/40, 20/50 or even 20/70 in the other, helps the vision of the better eye. With my vision reduced to 20/40 I could read day signals perfectly at one-half mile, night signals at 4,000 feet, and with 20/80 at 500 feet and 800 feet, respectively. The fireman has about all he can attend to on a limited train

without assuming an engineman's responsibiliity; further, there should be no excuse for using him in such an emergency, by simply changing

the clause to read as it does in the other reports, or as it does in the reports from which it was evidently adopted, i. e., that of the Dutch State Railway.

For the post of engine driver or stoker, * * * on looking with both eyes open, visual acuteness of at least 3/4 (without glasses) with each eye separately,

* * *

Fig. 13. Blurring effect produced by engine
running at high speed.

that it gives him little inconvenience. It has been urged that if an engineman with only one. good eye got a hot cinder in it he would be of little use. That is true; but it must be remembered that in the cab there is always a fireman with a second pair of good eyes, ready to take up the work in any such emergency until assistance can be obtained, and also, even if the engineman had two good eyes, the pain and flow of tears which would be caused by the hot cinder in one eye would prevent a satisfactory use of the other.

In reply to this, in the first place, Dr. Williams admits that the man is not so safe a man and should be "assigned a less trying run." Further, I contend that with 20/30

This would fully cover the entire field of contention.

Magnus and Würdemann give as the minimum amount of vision for enginemen 75 per cent of the scientific standard (6/VI), which is equal to 6/VIII, or approximately 20/XXX, "which is practically a perfect working or economic standard of vision."

Applicants for entrance into service possessing 12 D. of hyperopia or over, should not be accepted, for the reason that they will need glasses to bring their vision up to the required standard at the age of 35 or 40.

At this point the subject of glasses must be considered, and from my experience I would heartily indorse a clause to the effect that if

the vision of those examined for promotion after five years' service and those re-examined in service fell below the standard required, and such vision could be brought up to the required standard by glasses, they be promoted or retained in service. "Glasses must be worn if they are necessary to secure adequate vision." It is my unbiased opinion that protection to the eyes by lenses, more especially if needed to correct any refractive error, are of great benefit, and such opinion has been arrived at with a great deal of thought and careful study of the few objections to glasses for trainmen. The reports of Dr. J. de Lantshure and Dr. J. A. Denney as to the diminution of vision after long runs, I think can be easily explained. The men undoubtedly had more or less latent hyperopia, and the constant accommodative effort so tired the ciliary muscle that vision was somewhat reduced after a long run.

The color tests are of equal importance with visual acuity, and all reports agree in the use of the Holmgren wools.

The use of a lantern for a control test is a good idea, but why in the examination with the Holmgren wools is the following rule given: "No names should be mentioned in connection with any color in the above worsted tests; the tests should be based only on a comparison of colors," and with the lantern test, "have the person being examined call the names of the colors shown.”

The value of the color test is to determine whether the person examined can distinguish between various shades and degrees of intensity of color, so they can be sure of a signal if its intensity is reduced by atmospheric conditions, smoky or dirty lenses, or improperly regulated illumination. It has been stated many times that men can distinguish without any hesitation between danger, caution or clear colors, displayed of varying degrees of intensity, but fall down at once if required to name the col

ors.

Again quoting Dr. Williams:

I have found personally in the last few years four cases of men who passed the worsted test without any difficulty, who picked out these colors quickly and accurately, but when they looked at a distant signal, or when they looked at the testing lantern, especially with small

openings, they would often call a red light green, or a green light red; they were just as likely to mix up red and green as they were to get them right. This is due to a defect in the central portion of the retina. In such cases, when the colored object is large enough, or when it is placed near enough to the eyes, its image will extend beyond the affected parts of the retina, and its color can be at once recognized; but when the retinal image is small, as is the case wtih the light from a distant signal, which falls wholly within the affected area, it is easily mistaken. In order to get at the fact as to whether a man is thoroughly able to recognize his signals you need both a worsted test and a lantern test, the lantern coming nearer to the actual condition of night signals, where the man has nothing except the color to guide him.

Replying to this, I do not think a person with scotoma of sufficient magnitude to pass the worsted test and fail on the lantern test would have sufficient vision to pass the required visual standard. There is no doubt the lantern test is more nearly a road test and will seem more fair to railroad men, but it should be used only as a control test, not as a substitute for the worsted test.

The sections relating to the time of re-examination are unanimous, as also are those regarding the use of liquor.

The report should be accompanied with instructions for making the various tests and the use of the apparatus required.

CONCLUSIONS.

The result of my observations has been, in brief:

1. The best known standard of visual acuity and color perception should be required of men concerned in the active operation of trains.

2. The signal systems now in vogue, while they are not perfect, are sufficiently adequate for the standard of vision required and the present speed of trains.

3. Certain physical and accidental conditions about engines interfering with vision can not be overcome unless the position of the enginemen can be changed.

4. Certain atmospheric conditions interfering with vision can not be overcome; others can be mitigated or entirely relieved by the use of some form of protection to the eyes.

5. Glasses are not a hindrance to enginemen, and their use should be allowed when required

to protect the eyes or to bring the vision up to required standard, but no person should De accepted into service requiring them or who will accept a plus lens of 11 or 2 D.

6. With four reports emanating from four different sources of equal merit and standing, and all different in small details, the obtaining of perfect uniformity in examination of ran way employes is out of the question, as it can not be expected that the officials of different roads will all decide on the same report.

7. Furthermore, state legislation on the subject of vision and color perception of railway employes is being seriously considered, two states, Massachusetts and Ohio, having statutes regulating this. As nearly all railroads pass through a number of states, it would be well for the societies from which these reports emanate to agree in all details, as the state laws will necessarily be based on them, and if different states have different standards, an engineman qualifying in one and not in another, with his run extending in both, would be in serious difficulty.

9,816. Sec. 1. Be it enacted by the general assent of the State of Ohio that no railroad company shall hereafter contract to employ any person in a position which requires him to distinguish form or color signals, unless such person within two years next preceding has been examined for color blindness in the distinct colors in actual use by such railroad company, and has competent person employed and paid by the railroad company, and has received a certificate that he is not disqualified for such position by color blindness in the colors used by a railroad company. Every railroad company shall require such emplove to be re-examined at least once within every two years at the expense of the railroad company, provided that nothing in this section shall prevent any railroad company from continuing in its employment any employe having defective sight in all cases where such defective sight can be fully remedied by the use of glasses or by other means satisfactory to the person making such examinations. (As amended March 3, 1888.)

employes who will be at all concerned with the active operating of trains, or in giving or receiving signals.

Sec. 2. That a trained ophthalmic surgeon be selected by each company, who shall instruct and examine the men selected by the company to make these tests, shall recommend the standards and methods to be used, shall see that the equipment furnished to each examiner is. sufficient, that it is kept in proper order and renewed when necessary, and who shall be the authority to whom the doubtful cases shall be referred for final settlement.

Sec. 3. That the hearing be tested by the spoken word of the examiner and by a watch or acoumeter, and that for entrance to the service a candidate be required to repeat correctly words or numbers spoken in an ordinary conversational tone at a distance of twenty feet; or, for re-examination, at a distance of ten feet.

Sec. 4.-The acuteness of vision should be tested by the test types of Professor Snellen. or those which conform to his standards, which should in all instances have the same intensity and source of illumination.

Sec. 5. There should be two general standards of visual and aural requirements, viz., one for new men hoping to enter the service, and to be actively engaged in the operation of trains, and in giving and receiving signals; and one for those men engaged in similar work who have been uninterruptedly in a company's service for five years, either the company from which employment is sought, or some other company enforcing similar regulations. These latter may be regarded as old employes.

Sec. 6. The following minimum requirements should be adopted for acuteness of vision:

CLASS A.

Enginemen (road service), firemen (road service):

Entrance to Service.-20/20 in each eye test

SUGGESTIONS FOR A UNIFORM REPORT BY THE

AUTHOR.

Section 1.-It is essential that railroad corporations should require definite and scientific examinations of the sight and hearing of those

sess more than 12 D. of apparent hyperopia.

Re-Examination of Those in the Service.Enginemen shall not be retained in their positions if vision sinks below 20/40 in one eye and 20/30 in the other, or 20/20 in one eye and 20/50 in the other, unless such vision can