Everyone knows that the French Revolution was a historical and political event of global importance, but not everyone knows that it was also the age of the metric revolution. The French Revolution didn’t just shake up France’s system of government, it also brought about far-reaching changes to the methods of measurement in use.
In 1789, France’s revolutionary government faced a tricky challenge: every one of the fractured, divided regions of France had its own arbitrary system of measurement. The units of measure were effectively set by the local leaders of each village and district (none of whom had ever seen a meter)… depending on the geography of each area. These units took many different forms: grain, the denier (a unit for fibers and thread), ounces of various kinds, and even the weight of grape pomace left over after pressing (marc). The length of a “foot” used in Paris was different from the one used in Besançon, in eastern France, while the volume of jars and barrels was measured in boisseaux (a boisseau equaled about eight of today’s liters).
To ease trade between cities and avoid confusion, the leaders of the Revolution decided to set up a special committee to examine the question of weights and measures in the Republic. The committee, led by the greatest French scientists of the day, determined that France should adopt a new, universal and logical system of measurement based on “the natural order of the universe.” To define the new unit of length, a mission was appointed in 1792, headed by two astronomers, Jean Baptiste Delambre (1749-1822) and Pierre François-André Méchain (1744-1804). Delambre and Méchain decided that the Earth itself would serve as the basis for measurement, and defined the new unit of length as one ten-millionth (1/10,000,000) of the distance between the North Pole and the equator, measured along the meridian running through Paris.
Only a few years passed before, on April 7, 1795, the National Assembly declared the meter (from the Greek word “metron,” meaning “measure”) the official unit of length, along with new standards for weight (the gram) and volume (the liter). This unity of measurement brought reliable trade and contributed to the economy and unification of France, and in fact marked a fresh, clean break from the flawed monarchy that had just been toppled. The good news of the “meter” spread quickly across France, and Napoleon’s conquests helped it spread across Europe. Napoleonic France was, of course, destined to fall, but the new order remained in place, since many countries recognized the logic behind the metric system and adopted it themselves even after gaining independence. The system also won converts beyond the continent, and apart from a handful of English-speaking countries that still stubbornly cling to inches and yards, the metric system is now the one used across most of the world.
Back to 1796… to win over the French population and encourage the use of the new units, the revolutionary government decided to distribute measuring devices across the country and place them in busy, crowded spots. From the start of 1796 until late 1797, about 16 public measuring devices known as “mètre étalon” were installed in Paris. These “mètre étalon” were essentially protruding marble ledges on which the length of a “meter” was marked, letting people measure against it or copy it down. Of those 16 remarkable installations, only one has survived in its original location: a magnificent, stone-carved relic of that “revolution of measures.” Under the arcade at 36 rue Vaugirard, right across from the Senate building at the Palais du Luxembourg, you’ll find the marble ledge with the word METRE inscribed above it.
To be fair, another one of these standards exists on the façade of the Ministry of Justice, at Place Vendôme (13 place de la Vendôme), though unlike the first one, this isn’t its original location.
And you can’t write about the metric system without mentioning this immortal clip:
So next time you’re relaxing in the Luxembourg Gardens, stop by the original “mètre étalon” and take in that revolutionary relic. And while you’re at it, maybe measure your waistline too, just to make sure you haven’t overdone it with Paris’s culinary sins…
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