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satisfactorily have received the final approval of the board.

These two, which have been tested under actual traffic conditions, are both of the mechanical trip type. One of them, known as the Rowell-Potter trainstop, is an arrangement by which a bar lying parallel and close to one of the rails of the track is lifted a short distance above the rail whenever the visual signal is set for danger. Under such circumstances, the bar, coming into contact with

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THE S. H. HARRINGTON MECHANICAL
TRIP AUTO-STOP.

One of the two approved by the
government board.

MECHANICAL TRIP STOP WHICH OPERATES FROM THE GROUND.

an air-brake valve, suspended from one of the trucks of the tender, opens the valve and applies the brake.

Bars at the side of the track are provided in duplicate at each signal point, one of them 180 feet in advance of the other, so that, if the first one should by any accident fail to operate, the second would bring the train to a halt. Power to operate the stop, as well as to work the semaphore signals of the system, is derived from the pressure of the wheels

of passing trains on levers fixed close to the rails, these levers serving to wind up a coil spring.

The other automatic stop approved by the board is the invention of S. H. Harrington, and has been in experimental and successful use for over two years on the Northern Railroad of New Jersey. It works "overhead"-that is to say, the device fixed at the roadside is suspended, fifteen feet above the track, in such a way as to come into contact with a projecting arm of an air-brake valve on the top of the cab in the locomotive, the opening of which valve applies the brake. The roadside contrivance consists of a weight suspended on the end of a chain, which, hanging free, operates the engine valve by its mere inertia, when it strikes. At the same time, it has the great advantage of failing to work when a train is going very slowly-say, five miles an hour or

less.

Under such circumstances-when

a precaution of the kind is not wantedthe weight simply drags over the operating rod on the locomotive, producing no effect.

It will be observed that the automatic stop does not in any way insure the correctness of signals. Its only function is to correct the error of the engineman who runs past a danger warning. This, however, is of utmost importance, inasmuch as many bad accidents are caused by the failure of locomotive engineers to observe, understand, and obey signals. Failure to observe them may be due to fog, snow, extinction of signal lights, or smoke from other trains. The engineman may fail to understand signals because of their complexity, or for the reason that his attention is distracted. Intentional failure to obey them is rare. The automatic stop, however, eliminates almost entirely the element of human fallibility. Furthermore, experience has shown that engineers are much more careful to heed danger signals when it is certain. that disobedience of such signals will be detected.

The board confidently expects that the automatic stop will be developed to a point where, like the block signal, the car-coupler, and the train-brake, it will be available to railroads generally, and will greatly contribute to the safety of train operation. Already such contrivances are in actual use to some extent-for example, on the Boston Elevated, the New York City Subway, the Philadelphia Subway, and the underground lines in London, England. Mechanical trip train-stops of similar design, worked by electric motors, are also in use in the tunnels under the Hudson River between New York and Hoboken. Officers of these roads are unanimous in testifying to their satisfactory operation, and

on a number of occasions they have been the means of preventing collisions.

The board has likewise offered to make practical tests of two kinds of cab signals, to which an automatic train-stop can be attached if desired. One of these is the invention of E. F. Clement, of Philadelphia. The other is owned by the Railway Audible Signal Company, of London, and is now in use on the Great Western Railroad in England. Its essential feature is a short contact rail in the middle of the track at the signal point. This rail engages with a device beneath the engine, showing a danger signal in the cab and blowing the whistle of the locomotive.

The board has found itself called upon to give a good deal of consideration to the question of locomotive headlights. In seven States of the Union, Arkansas, Montana, North Carolina, Oklahoma,

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ELECTRIC AUTOMATIC STOP ON TROLLEY LINE IN WASHINGTON STATE. When the signal is set for danger, a metal rod smashes a glass tube on top of the car, and thus sets the brakes.

South Dakota, Texas, and Washington, headlights of 1,500 candlepower or over are required by law. The State railroad commission of Indiana compels the use of equally powerful headlights, and in Georgia the law demands electric headlights of great luminous efficiency, with reflectors twenty-three inches in diameter.

The trouble with the ordinary oilburning headlight, commonly employed on locomotives is that it is seldom powerful enough to make it more than a marker to indicate to persons at stations or

railways crossings, or to trains on other tracks, that an engine is approaching. For discovering or identifying distant objects on the track

TRAPPED THUS, MANY A PERSON HAS BEEN KILLED BY TRAINS.

All frogs are now required to be blocked with metal or wood.

ahead, it is of almost no use at all. Hence the argument in favor of the high-power headlight, gas or electric, by which persons or obstructions may be seen at a sufficient distance to enable the train to be stopped before reaching them.

On the other hand, there are some serious objections to the high-power, headlight, chief among which is the fact that its rays are so intense as fairly to blind, for the moment, persons who may look into the beam. This effect, when experienced by enginemen of trains running in an opposite direction on parallel tracks, is likely to give rise to accidents. Furthermore, it is often difficult to read the colors of signal lamps correctly in the beam of an electric headlight, the spectrum of the arc being very rich in blue and green rays, and containing a

relatively small proportion of the red and yellow. On this account particularly the railroads have made strenuous objection to such headlights. On double-track roads, and particularly on roads having three or four tracks and equipped with signals placed at frequent intervals, the prevailing opinion seems to be that electric headlights are not only unnecessary, but are likely to cause serious errors on the part of engineers in reading colored signal lights.

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An incidental problem which the board is trying to solve is that of the headlight which shall continue to throw its beam upon the track while the engine is rounding a curve. Inasmuch as such lights are usually fixed in position, their rays are projected in the direction of the axis of the locomotive, and hence on curves do not illuminate the track ahead. Various devices have been submitted for imparting to the headlight, while the engine is rounding a curve, such motion as will turn the beam so as to make it fall on the track. Most of these contrivances, however, are very crude, attempting to use the slewing of the front truck of the engine to rotate the headlight, and not one of them has been found satisfactory.

The board strongly recommends that railroads all over the country be compelled by law to adopt and maintain the block system for running their trains. At the present time only about sixty-six thousand miles of railroads, out of a

total of approximately two hundred and forty thousand miles in this country, are operated under this system, notwithstanding a superabundance of evidence that, wherever used, it has added immeasurably to safety of transportation. The situation is not unlike that which existed at the time when the adoption of car couplers and power brakes was compelled by Federal enactment, against a most determined opposition on the part of the companies, desirous of avoiding the expense involved in the acquisition of such improvements.

As a matter of fact, the adoption of the block system everywhere would cost

the railroads very little money. Not much apparatus is required. In July of last year, the Baltimore & Ohio line from Storr's, Ohio, west to Vincennes, Ind., and from North Vernon, Ind., to New Albany, over one hundred and eighty miles, was equipped with all the necessary outfit for the operation of the simple manual block system in less than one week.

It is the opinion of the board that the compulsory introduction of the block system on all railway lines will tend greatly to reduce the number of collisions and the incidental mortality record that results therefrom.

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