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Weights and Measures: International

The meter, unit of length, is nearly the ten-millionth part of a quadrant of a meridian, of the distance between equator and pole. The International Standard Meter is, practically, nothing else but a length defined by the distance between two lines on a platinum-iridium bar at 0° Centigrade, deposited at the International Bureau of Weights and Measures, Paris, France. The liter, unit of capacity, is derived from the weight of one kilogram pure water at greatest density, a cube whose edge is one tenth of a meter and, therefore, the one-thousandth part of a metric ton. The gram, unit of weight, is a cube of pure water at greatest density, whose edge is one hundredth of a meter, and, therefore, the one-thousandth part of a kilogram, and the one-millionth part of a metric ton.

The metric system was legalized in the United States on July 28, 1866, when Congress enacted as follows: "The tables in the schedule hereto annexed shall be recognized in the construction of contracts, and in all legal proceedings, as establishing, in terms of the weights and measures now in use in the United States, the equivalents of the weights and measures expressed therein in terms of the metric system, and the tables may lawfully be used for computing, determining, and expressing in customary weights and measures the weights and measures of the metric system."