Page:Popular Science Monthly Volume 64.djvu/401

Rh The subdivisions and multiples of these standards were such as to necessitate much confusion. The troy pound was divided into 12 ounces of 480 grains each, and the avoirdupois pound into 16 ounces of 437.5 grains each. The troy pound is less than the avoirdupois pound and the troy ounce greater than the avoirdupois ounce. A distinction has to be made additionally between dry ounces and fluid ounces. Various bushels and tons of widely different values continue in use. Although the original English standards were destroyed by fire in 1834, they were subsequently reproduced with reasonable accuracy. They are now the standards of the British empire with a total population of nearly 400,000,000 people, among whom a multitude of other unstandardized units of weight and measure are in current use.

The American colonies naturally employed such coins, weights and measures as were used in the mother country, and in no two of them were the 'systems' alike. A decimal system of currency proposed by Thomas Jefferson was introduced in 1792 and has continued in satisfactory use ever since. In taking this rational step the American republic set an example which has subsequently been followed by a large majority of the civilized nations of two hemispheres. Different monetary units are employed, such as the dollar, the franc and the florin, but the great advantage of decimal multiplication and division is almost universally recognized. The constitution authorizes congress to fix all standards of weight and measure for the entire country, and Mr. Jefferson urged the adoption of a decimal system for these as well as for our coinage. But this plan was not followed, and now after the lapse of a century American weights and measures are still in a state of confusion; some of them reasonably definite, others unintelligible except by the use of qualifying circumlocutions, and none of them connected by very simple numerical relations. A copy of the English yard was tentatively adopted in 1814 as the American linear standard. A copy of the troy pound was in 1828 made the standard of weight for the mint, and in 1830 the avoirdupois pound, deduced from the troy pound, was legalized as the standard of weight for ordinary commercial transactions. At the same time the wine gallon of 231 cubic inches was adopted as the standard of capacity for liquids, and the Winchester bushel of 2,150.42 cubic inches for solids. It will be observed, therefore, that the British gallon exceeds the American gallon by 20 per cent. The British bushel contains 2,218.192 cubic inches, and thus exceeds the American bushel by a little over 3 per cent. If we speak of a gallon or bushel, the meaning is thus not clear without further specification. But without reference to English units, or units that are obsolete or infrequently employed, we have in general use in America two different pounds, two different ounces, two different quarts, two different tons, two different miles, and a complex relation between linear, square