Page:Popular Science Monthly Volume 49.djvu/200

THE METRIC SYSTEM.^[1]

By HERBERT SPENCER.

(With a Letter from Sir Frederick Bramwell.)

I.

ADVOCATES of the metric system allege that all opposition to it results from "ignorant prejudice." This is far from being the fact. There are strong grounds for rational opposition, special and general; some already assigned and others which remain to be assigned. I may fitly put first a carefully-reasoned expression of dissent from a late man of science of high authority.

In 1863 Sir John Herschel published an essay, in which, after referring to an attempt made during the preceding session to carry through Parliament a bill establishing the French metrical system in this country, and anticipating that the bill (said to have been confirmed in principle) would be again brought forward, he proceeded to contrast that system with a better one to be reached by making a minute modification in our own unit of measure. The following extract will sufficiently indicate the line of his argument:—

Let us now see how far the French metre as it stands fulfills the requirements of scientific and ideal perfection. It professes to be the 10,000,000th part of the quadrant of the meridian passing through France from Dunkirk to Formentera, and is, therefore, scientifically speaking, a local and national and not a universal measure. . . . The metre, as represented by the material standard adopted as its representative, is too short by a sensible and measurable quantity, though one which certainly might be easily corrected.
[In the appendix it is shown that according to the latest measurements the error is 1-163d part of an inch on the metre.]

Sir John goes on to say that "were the question an open one what standard a new nation, unprovided with one and unfettered by usages of any sort, should select, there could be no hesitation as to its adoption (with that very slight correction above pointed out)"; and he then continues—

The question now arising is quite another thing, viz.:—Whether we are to throw overboard an existing, established, and, so to speak, ingrained system—adopt the metre as it stands for our standard—adopt, moreover, its decimal subdivisions, and carry out the change into all its train of consequences, to the rejection of our entire system of weights, measures, and coins. If we adopt the metre we can not stop short of this. It would be a

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1. Most of the matter in this article appeared originally in the form of unsigned letters in the London Times. The interest in the subject in the United States warrants its repubication in the Monthly, with a view to which Mr. Spencer has kindly consented to allow his authorship of the letters to be made known.