Page:Popular Science Monthly Volume 64.djvu/403

Rh the imposition was laid never really adopted it. The succeeding generations have been gradually losing the memory of the old weights and measures, and the inherent merits of the new system are such that relapse to the old barbarism is now impossible, whatever may be the modifications gradually imposed in practise upon a system of metrology which owed its existence to special creation rather than evolution. The case is quite comparable with the new era of sanitation in Cuba. Yellow fever has been almost wholly stamped out. The superiority of the new conditions is now recognized, and the Cubans will probably never return voluntarily to the régime of filth which fixed a scourge upon Havana for two centuries.

Prior to the French revolution various propositions and experimental attempts had been made to secure an absolute standard of length. In England Graham had tried to establish the length of a seconds pendulum as a standard, but without permanent success. In France several years were devoted by Delambre and Méchain to the determination of the length of an arc of the meridian between Dunkirk and Barcelona. The quadrant as computed from this survey was 10,000,000 times the length of the adopted standard, the meter. The outcome was no more absolute than any other product of human skilled labor. The opponents of the metric system have been fond of calling attention to the mistake in computed value of the meter. The labors of Bessel, Schubert and Clarke have established the existence of an error of about one part in 7,000. This means that the meter is shorter than it ought to be by an average hair's breadth; but this small error is quite sufficient to prove that the actual meter is an arbitrary standard. The fact is admitted as readily by the advocates as it is proclaimed by the opponents of the system. The most enthusiastic of these opponents have been the members of a small clique, led by the late Piazzi Smyth of Edinburgh, who claimed to have discovered in the pyramids of Egypt convincing evidence that the British inch is the only absolute unit, a definite fraction of the earth's polar diameter. Such conclusions are quite harmless ; equally unassailable and incapable of proof. The real merit of the metric system is found in its definiteness and simplicity, and not at all in any approximate relation between its fundamental unit and the earth's polar circumference, or any other terrestrial dimension, whatever may have been the intention of its originators.

The metric system was adopted in France in 1795 and made obligatory in 1801. The change was too sudden for the people and compromise was found necessary. The full enforcement of the law dates from 1840, and the system has since become gradually and quite thoroughly established. France is a republic, and the law would long ago have been repealed if good reason for such action existed. At the close of the Franco-German war an important step in the unification of the