The 22nd of June 1799, is the official birthday of the meter and with that the metric system. As with the infamous decimal time system (10 months ASF), the meter is a result of the French Revolution. On this day, 200 years ago, the length of a meter was finally decided, by measuring the distance between Dunkerque, France and Barcelona, Spain. This gave the length of the earth meridian and the length of the meter was defined as a 10th millionth part of a quarter of the meridian. This length was then made into a ruler, made of platinum, and deposited in the National Archive of France.
A call was made to “all civilized countries” to join the new system, meaning the countries France ruled, Spain and Denmark (!) and copies of the ruler was distributed around the French realms and those of the other two countries.
Many of the copies were attached to the facades of buildings, typically near market places.
The rest of the metric system was derived from this meter. The original length gave us the millimeter (1/1000 of a meter), centimeter (1/100), decimeter (1/10) ASF. A liter is defined as one cubic decimeter of water.
Nowadays we now that the platinum ruler in fact was 0.2 millimeter too short and a meter is now defined as being 1.650.763, 73 wavelengths of a spectral line of krypton 86.
Living in one of the countries embracing the metric, I just wanted to say congratulations and Happy Birthday. Given another 200 years, the US might have adopted it too.
When in trouble or in doubt, run in circles, scream and shout