All coins have a relative and interchangeable value based upon their weight and fineness.  Weights and measures remain the same by whatever unit they may be expressed; but, primarily, time can only be measured by a standard actually or apparently in motion.  Absolutely accurate mean local time, varying, as it does, by infinitesimal differences at every point in the circuit of the earth, may be shown on a stationary object, but cannot in general be kept by an individual or object in motion.  The mean local time of some fixed point in each locality must be taken as the standard for practical use.  The important question to be determined is, over what extent of territory, measuring east and west from such fixed point, its mean time may be employed for all ordinary purposes without inconvenience.  This can be absolutely determined only by practical experience.

Careful study of this phase of this subject led, perhaps, more directly than any one single cause, to the proposal of the detailed system of standard time which now satisfactorily controls the operations of one hundred and twenty thousand miles of railway in the United States and Canada, and governs the movements of fifty millions of people.

Before the recent change there were a number of localities where standards of time were exclusively employed which varied as much as thirty minutes, both on the east and the west, from mean local time, without appreciable inconvenience to those using them.  From this fact the conclusion was inevitable that within those limits a single standard might be employed.  The result has proved this conclusion to have been well founded.

No public reform can be accomplished unless the evil to be remedied can be made plainly apparent.  That an improvement will be effected must be clearly demonstrated, or the new status of affairs which will exist after the change, must be shown to have been already successfully tried.  Here, as in law, custom and precedent are all powerful.  It would be a difficult task to secure the general adoption of any system of time-reckoning which cannot be employed by all classes of the community.  Business men would refuse to regard as a reform any proposition which introduced diversity where uniformity now exists, nor would railway managers consent to adopt for their own use a standard of time not coinciding with or bearing a ready relation to the standard employed in other business circles.  To adopt the time of a universal day for all transportation purposes throughout the world, and to use it collaterally with local time, would simply restore, and possibly still more complicate, the very condition of things in this country which the movement of last year was intended to and did to a great extent obviate.  Railway managers desire that the time used in their service shall be either precisely the same as that used by the public, or shall differ from it at as few points as possible, and then by the most readily calculated differences.  The public, on the other hand, have little use for absolutely accurate time, except in connection with matters of transportation, but will refuse to adopt a standard which would materially alter their accustomed habits of thought and of language in every-day life.  That this position is absurd may be argued, and, perhaps, admitted, but it is a fact, and one which cannot be disregarded.