Metric System Pioneer
In 1893, Thomas C. Mendenhall, a native of Hanoverton,
Ohio, decided that the international meter and kilogram would be the
fundamental length and mass standards for weights and measures in the United
States. Mendenhall was then Superintendent of Weights and Measures for the
U.S. federal government. His decision, known as "The Mendenhall Order," was a major
departure from past United States policy of maintaining length and mass
standards identical to the Imperial systems of weights and measures used in
Great Britain. In that system, length was the English yard and mass the pound.
(1841-1924) was a renowned scientist, appointed by President James Harrison as
superintendent of the U.S. Coast and Geodetic Survey in 1889. He had been
chairman of physics at Ohio State University, chief of the Instrument Division
in the U. S. Signal Corps, and president of Rose Polytechnic Institute.
The Mendenhall Order redefined customary British-U.S.
units in terms of metric units. The yard became 3600/3937 meter and the
avoirdupois pound-became the mass of 0.4535924277 kilogram. The National Bureau of Standards
(now the National
Institute of Standards and Technology) used those same definitions from its
founding in 1901 until 1959. In 1959, English-speaking countries agreed to
define one yard as 0.9144 meter and one pound-mass as 0.45359237 kilogram.
Mendenhall did not need any new laws for the
action because the metric system had been legal in the U. S. since passage of
the Metric Act of 1866. It regarded metric units as the fundamental and
internationally accepted standards for the United States.
President Harrison appointed Mendenhall director
of the U.S. Coast and Geodetic Survey in1889, and he served until 1894. The
weights and measures office then was part of the geodetic survey. Mendenhall
helped to determine the boundary line between the United States and Canada,
including the boundary of Alaska. As a member of the International Electrical
Congress, he also had a hand in defining basic units of electricity.
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