In which country? The Metric System was invented in
post-Revolutionary France to replace a vast and utterly chaotic
collection of trade-invented units, often varying regionally.
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Britain used the Imperial system (inch, foot, pound-avoirdupois,
gallon, etc), and that spread to America and many other countries,
albeit with some changes such as the difference between UK and US
gallon. Other countries had their own units: I found one used the
delightfully named "pood" for mass, but I don't know which!
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Nowadays the Systeme Internationale version of the Metric System
is used world-wide, both nationally and internationally, for trade,
sports, science and engineering.