Elementary arithmetic, with brief notices of its history... by Robert Potts.

14

WEIGHIITS AND MEASURES.

Fahrenheit's thermometer, the barometer being at 30. inches, is
59'8935-8 inches of the Parliamentary standard. And that according
to the same scale of inches, a cubic inch of pure distilled water, at 66~
of Fahrenheit, when the barometer is at 29-74 inches, weighs 252'422
Parliamentary grains.
In 1814 a Select Committee was appointed under the Privy Seal,
to inquire into the original standards of weights and measures in the
kingdom, and into the laws relating thereto. They state in their
report that the Statute Book from the time of Henry III. abounds with
laws for maintaining an uniformity of weights and measures throughout the realm. They remark that the measures prescribed in the
Exchequer are at variance with one another, and, as the law stands,
all of them are considered to contain like quantities; that the laws
are at variance with one another, and that exceptions are allowed in
different counties, as well as in some articles of merchandise. They
attribute the chief causes of the existing inaccuracies to the want of
a fixed standard in nature, and a simple mode of connecting measures
of length with those of capacity and weight. In order to compare
the standard of length with some invariable natural standard, they
reported that it appears from the experiments made for determining
the length of a pendulum vibrating seconds in the latitude of London
in a vacuum, and reduced to the level of the sea, that the distance
from the axis of suspension to the centre of oscillation of such pendulum is 39'1393 inches, of which the standard yard contains 36.
Next, that the weight of water contained in any vessel affords the
best measure of its capacity. If the standard gallon of water weigh
10 pounds avoirdupois and contain 276'48 cubic inches, the quart will
weigh 40 ounces and contain 69-12 cubic inches, and the pint will
weigh 20 ounces and contain 34'56 cubic inches. And such a simple
connection between the standards of weight and measure of capacity
will most likely tend to preserve from error the uniformity of these
measures. And in this manner the standard of length is kept
invariable by means of the pendulum, the standard of weight by the
standard of length, and the standard of the measure of -capacity by
that of weight. The Committee concluded their report with twenty
resolutions for the consideration of the legislature.
It does not appear that these recommendations were so far
approved by the House as to enter upon legislation; but in 1818 a
Commission was appointed further to consider the subject of weights
and measures, and the Commissioners made their first report in 1819.
In the appendix to their report they make the following remarks:"A general uniformity of weights and measures is so obviously
desirable in every commercial country, in order to the saving of timo,
the preventing of mistakes, and the avoiding of litigation, that its
establishment has been a fundamental principle in the English Constitution from time immemorial; and it has occasionally been enforced
by penal statutes, and by various other legislative enactments. At
the same time, it has commonly been considered as one of those.
objects which cannot, consistently with logical accuracy, with natural
justice, and with the liberty of the subject, be very precisely defined,
or very peremptorily and arbitrarily enjoined on every occasion; and
there are many instances in which a departure from complete unifom nity is not only tolerated, but established by law. It must, indeed,
sometimes be almost as impossible to control the despotic influence