reality they may both have varied.

The current law defines the kilogramme as the standard of mass, and
the law is certainly in conformity with the rather obscurely expressed
intentions of the founders of the metrical system. Their terminology
was vague, but they certainly had in view the supply of a standard for
commercial transactions, and it is quite evident that in barter what
is important to the buyer as well as to the seller is not the
attraction the earth may exercise on the goods, but the quantity that
may be supplied for a given price. Besides, the fact that the founders
abstained from indicating any specified spot in the definition of the
kilogramme, when they were perfectly acquainted with the considerable
variations in the intensity of gravity, leaves no doubt as to their
real desire.

The same objections have been made to the definition of the
kilogramme, at first considered as the mass of a cubic decimetre of
water at 4° C., as to the first definition of the metre. We must
admire the incredible precision attained at the outset by the
physicists who made the initial determinations, but we know at the
present day that the kilogramme they constructed is slightly too heavy
(by about 1/25,000). Very remarkable researches have been carried out
with regard to this determination by the International Bureau, and by
MM. Macé de Lépinay and Buisson. The law of the 11th July 1903 has
definitely regularized the custom which physicists had adopted some
years before; and the standard of mass, the legal prototype of the
metrical system, is now the international kilogramme sanctioned by the
Conference of Weights and Measures.

The comparison of a mass with the standard is effected with a