Popular Science Monthly/Volume 26/December 1884/The Reformation in Time-Keeping
|THE REFORMATION IN TIME-KEEPING.|
ON November 19, 1883, the daily papers of the United States and Canada, from, the Atlantic Ocean to the Rocky Mountains, contained more or less elaborate accounts of the change from local to "standard time" which had been made on the previous day. Comparatively few among the millions of people who read these accounts took the trouble to investigate the actual meaning of the change or the arguments in its favor. It appeared to be the work of practical railway managers, and to be favored by leading scientists. Watch-makers agreed to and aided the change, and few other persons were apparently interested. So the people quietly acquiesced, reset their watches a few minutes faster or slower, and for the most part soon forgot that any but "standard time" had ever been in use.
In the present generation we have become so accustomed to the use of accurate time and the ready means of obtaining it, that we hardly realize how dependent we are upon it. Were it possible to suddenly destroy all clocks and watches in any given center of population among civilized nations, while all other surroundings of modern development remained as before, we can scarcely conceive of the endless confusion that would arise. Only by contemplating the results of such a catastrophe can we fully understand what an important part the knowledge of accurate time plays in our every-day affairs.
Man shares with the inferior animals the knowledge and the use of the simplest and earliest division of time into day and night, and in a more restricted sense into seasons. The division of the day into minor parts has been developed by man as necessity or convenience required. It has not been many years since watches were made with hour-hands only, and the general use of the finer divisions into minutes and seconds is almost entirely the outgrowth of the requirements of modern civilization. Astronomical time-keeping is not here considered. By the Babylonian system of dividing the day, which was used by the Jews and other Oriental nations, the time between sunrise and sunset was portioned into twelve equal parts at all seasons of the year, the hour varying in length with the season. If this method of division still prevailed, the hours in New York city would vary in length from about forty-six to about seventy-five of our present minutes. In the Arctic regions the inapplicability of this system to general use would reach its climax of absurdity.
The general facts upon which all systems of time-keeping are based are commonly understood, but the details are seldom referred to.
The most primitive kind of timepiece is a sun-dial. Reduced to its simplest form, a sun-dial consists of a straight pole erected upon a permanently fixed circular plate, the shadow of the pole indicating midday when it coincides with a line drawn due north from the base of the pole, the pole being erected upon a line parallel with the axis of the earth. The other hours of the day are indicated by marks upon the circular plate upon which the shadow of the pole successively falls.
When the sun-dial was invented can not be stated. It was of very ancient origin, and is mentioned in the thirty-eighth chapter of Isaiah. The clepsydra, or water-clock, and the hour-glass, although very ancient, must from their nature have been invented subsequent to the sun-dial. But sun-dials, of which there are about a dozen different kinds, although common, were never in such general use as clocks are in modern times, and were philosophical rather than popular instruments. The clock was invented about 1379, and the pendulum as a regulating power in 1657.
The rapid development of the science of horology in the present century has been almost coincident with and in no small degree dependent upon the construction and operation of railway and telegraph lines. The needs of these great engines of modern civilization created a general demand for exactness in time reckoning which had never existed before. It was required both for the use of their employes and for the public which patronized their lines.
A sun-dial being stationary, when properly made and adjusted, exhibited solar time correctly, and a watch regulated from the dial by the equation of time would also be correct for that particular spot, but the moment the owner of the watch began to move east or west his time-piece no longer registered correct time, and when he traveled with the speed of a railway-train the error was rapidly exaggerated.
The necessity for exactness before mentioned, and the impossibility of adhering to local time, early attracted the attention of railway managers, and caused them much perplexity and annoyance. With the rapid construction of railway lines, the commingling of the various local standards soon became decidedly intricate. Travelers were greatly inconvenienced by the lack of knowledge of the standard upon which the time of trains as advertised was based, and to such the situation was full of difficulties. Some of these difficulties were stated in an "open letter" published in "The Century" for September, 1883. The subject in its practical aspect also attracted the attention of scientists and scientific societies. It became a prominent topic of discussion at meetings of the American Metrological Society, the Association for the Advancement of Science, and the Society of Civil Engineers. Although astronomers use sidereal time, based upon the position of the stars, and not of the sun, in common with many other scientists they were generally warmly interested in the subject.
The local time kept by clocks is an average of solar time, and is properly designated "mean time," as distinguished from the variable time shown by the sun-dial. No clock or watch can be made to keep the time as shown by the sun-dial, and this new system of time-keeping, therefore, became necessary when clocks and watches were invented. The relation between mean and apparent time, and what is meant by "the equation of time," may be seen at a glance by reference to the accompanying diagram. Mean time being represented by the right line graduated for the several months of the year, the variation of apparent time is shown by the curved line entwined around it. In other words, a line drawn through the several positions of the sun at mean noon will describe the curves as indicated. For reasons which need not here be stated, the diagram will be found generally correct for one year only out of four; but, upon the scale by which the diagram is drawn, this error is infinitesimal. It is hardly necessary to state that the principal cause of the variation between mean and apparent time is "the obliquity of the ecliptic to the equinoctial."
Apparent time is about fifteen minutes slower than mean time about February 10th, and about sixteen minutes faster on October 27th. They agree about April 15th, June 15th, August 31st, and December 24th. If a well-regulated clock were set by apparent time on October 27th, it would be about thirty-one minutes faster than apparent time on the following February 10th. It will be seen that, under such circumstances, clock-time would vary as much from true sun-time as any clock set by the present system of standard time varies from mean time at the most extreme point.
The safe operation of a railway requires that the watches of all its Fig 1.—Diagram showing comparison of Mean (or Clock) Time with Solar (or apparent) Time, at the several Seasons of the Year. The perpendicular central time represents Mean Time, and the curved line Solar Time, at mean noon.differed by more than half an hour from mean local time at various points. The inhabitants of the surrounding country at such points, having no standard of reference except the railway-clocks, accustomed themselves to and used railway-time without inconvenience, and in a number of instances, where the railway standard was changed from some cause, the people made the same change in their time-pieces. It was important in connection with railway-trains to keep exact time, and for all other purposes any relative time was sufficiently accurate.upon, or who have occasion to refer to, the same trains should always indicate the same moment of time. Railway-time upon lines running east and west can of course never coincide with mean local time except at a single point, and the longer the line of the road the greater will be the variation. Before the recent change to standard time there were several cases where the railroad-time in use
In the early part of the year 1883 there were fifty-three standards of time in use on the railroads and by the people of the United States and Canada. These standards governed sections with no definite limits, and upon railroad lines were apparently inextricably mixed and interwoven. The condition of the matter was abnormal in numerous instances, there being no less than three hundred points where railroads, using different standards of time, crossed each other and exchanged traffic. At almost every city of importance several standards were used by the railways, and in some cases the city time differed from any of them. Local jealousies made the chance of effecting reform apparently hopeless. Many who warmly favored standard time regarded the reform as one unlikely to be soon accomplished.
The solution of the problem necessarily required a close and long-continued study of the peculiarities of the situation. Whatever change was proposed must affect as little as possible the relations which previously existed between railway lines and business communities.
A complete system of standard time was finally devised and submitted in April, 1883, to several railway conventions, assembled to consider other subjects, at which about fifty important companies were represented. The system proposed was deemed practicable, and recommended for adoption, by the railway officials present at these conventions. It involved the total abolition of the use of local time by the public, except at points situated on the governing meridians.
A theory of reform had been under consideration by scientific societies for years, and several systems of standard time had been proposed, founded upon this theory, without practical result. Many investigators of the problem among railway officials and scientists had independently arrived at the conclusion that this theory was the correct one. It was based upon the idea of grouping sections of the country together under the same standard with an even-hour difference between the standards of the adjoining groups. "Eastern standard time," which is the standard of the section in which Boston, New York City, Philadelphia, Washington, etc., are located, is simply the mean time of the seventy-fifth meridian west from Greenwich, and the time kept in all these cities is now precisely alike. The dotted lines on the right and left of the diagram represent the mean times formerly kept at New York city and Washington in their relation to "Eastern" standard time. If a curved line were projected on one of these dotted lines parallel with the curved line on the diagram, and at the same distance, its relation to the central perpendicular line would represent the relation which solar time at New York or Washington bears to the standard time of the seventy-fifth meridian.
In the various discussions of the question a difficulty arose in deciding upon the best governing meridian. Should it be Greenwich, Washington, or New York? Each had its advocates. If this question could be settled, a more serious one arose in determining the proper lines upon which the sections could be divided. The result of its adoption has proved that the system proposed in April, 1883, solved these questions satisfactorily. This system is now in force, and is represented in outline on the map which appears on page 150. It will be noticed that the dividing lines are irregular. Communities near the border which have adopted the system, use the standard east or west of their locations according to the direction in which their business interests lie. In other words, the question is determined by convenience of use, as questions in regard to time-keeping have always been determined. The peculiarities of ownership or operation of the railroads determine their points of change. Legislative enactment will doubtless ultimately define the precise boundaries of the sections of countries to be governed by each standard.
The action of the railroad companies having been assured, the subsequent action on the part of city governments became possible as it could not have been otherwise. Of the labor and means employed to secure this action on the part of the railways and the cities it is unnecessary here to speak. They proved sufficient to accomplish very fully the end desired. More than eighty per cent of all the cities of over ten thousand inhabitants in the United States have adopted standard time.
The adoption of the new standard required a simultaneous change to be made in the railway-clocks and the watches of employés upon nearly every railroad in the United States and Canada, the change varying from one minute and three seconds on the Pennsylvania Railroad to forty-five minutes on the Intercolonial Railway of Canada. The exceptions were two roads in the vicinity of New Orleans, and a few lines in the vicinity of Denver. The change was also slight for some of the St. Louis roads. The Intercolonial Railway adopted the time of the seventy-fifth meridian as a matter of convenience, instead of that of the sixtieth meridian, to which its location would have properly assigned it. So perfect were the preparations that not a single accident at any point is recorded as having been caused by the change. On the day when the new standards took effect, the clocks of about twenty thousand railway-stations and the watches of three hundred thousand railway employés were reset. Hundreds, perhaps thousands, of city and town clocks were altered to conform. How many individuals reset their watches it is impossible to compute, but they could certainly be reckoned by millions. Probably no such singular incident has ever before happened, or is likely to occur again.
At the present time, from the Atlantic Ocean at the eastern extremity of New Brunswick, to the Pacific coast at Oregon, the minute-hands of the railway clocks and watches indicate the same minute of time at all hours, and fully fifty million people regulate their business affairs by standard time.
While a few and for the most part unimportant communities, and some railway companies, did not make the change immediately, so large a majority adopted the system on November 18, 1883, that that date may be fairly taken as the one upon which the reform took effect. Several New England railroads, the Central Vermont Railroad being the most important, commenced to run their trains by "Eastern" standard time on October 7, 1883. The Central and Southern Pacific Railroads west of Ogden and Deming, and their branch lines, are the only railroads in the United States or Canada which do not now use standard time, if we except two purely local roads in Pennsylvania, aggregating less than twenty miles in length. The last to adopt the system were the Union Pacific Railway and the city of Omaha, on May 1, 1884.
The legality of the use of standard time was established by the decision of Judge Holmes, of Massachusetts, that whatever time was in ordinary use by the people of any community was lawful time; and his decision is not likely to be reversed. From an economic stand-point it is difficult to perceive what difference it makes to a laboring-man whether he commences work at a time nominally called seven o'clock or half-past seven, so long as he receives full wages for a full day's work.
Some of the objections raised to the use of standard time as a substitute for local time are as amusing as the famous declaration of the Rev. John Jasper, of Richmond, Virginia. It is urged that the sun was divinely set to rule the day, and therefore to use any but solar time is akin to, if not actually, immoral conduct. As the moon was also set to rule the night, such persons, if logical, should obey that portion of the divine command also. The fact is, that solar time was necessarily abandoned when clocks came into general use, and time based upon one or another arbitrary standard has governed the civilized world ever since. The present system, with its widely extended uniformity, simply conforms to the principle of securing the greatest good to the greatest number, a principle which must everywhere in the end prevail.