Metric System Day takes place on April 7 every year. Now often used as a synonym for the International System of Units (or S.I.), the metric system is a system of measurement used in most countries of the world except the United States and a few other countries.
The metric system was introduced by France in 1799 and it’s an original, decimal-based (based on powers of 10) measurement format based on meters and kilograms. Base units in the metric system include kilograms, meters, and liters.
The metric system also uses the Kelvin scale (or the Celsius scale) to measure the temperature. The decimal-based prefixes in the metric system include milli, centi, deci, and kilo. However, these prefixes are not used with the temperature degree.
The history of the metric system goes all the way back to 1586 when Flemish mathematician Simon Stevin published a leaflet titled ‘De Thiende’ (‘The Tenth’). In the pamphlet, Stevin emphasized the importance of measuring in decimals and predicted that one day, the world would use decimals in standard measurement.
Well, Stevin’s prophecies didn’t come true until over two centuries later when Napoleon became the emperor of France and in 1799 inaugurated the metric system.
As Napoleon’s European conquest advanced, he also introduced the metric system to his new territories. However, as soon as he was defeated at the Battle of Waterloo in 1815, France and most of Napoleon’s former colonies returned to using their old systems of measurement.
In 1837, France returned to the use of the metric system, and in 1840 — some 50 years after its inauguration — the system became compulsory throughout France.
Other countries such as the newly-formed Kingdom of the Netherlands formed in 1815 also adopted the use of the metric system in 1820 as a unified system of measurement. Similarly, the German Empire formed from the old German Confederation in 1871 continued to use the metric system.
In the same year, the newly-amalgamated Italy also opted for the metric system in preference to the former systems of measurement.
Between 1875 and 1914, other countries like Brazil, Spain, Portugal, Norway, Mexico, Argentina, Peru, Columbia, Sweden, Denmark, Finland, Paraguay, Philippines, and Vietnam also adopted the metric system. In 1866, the U.S. passed a law allowing Americans to use either the metric system or U.S. customary units for commercial purposes.
Many years later — precisely in 1897, the United Kingdom also passed a similar law allowing its citizens to choose between the metric system or Imperial units for trade.
