Paris 2024 – Metre

After the French Revolution, the metric system was adopted. On 16 spots in Paris the new metre was placed in marble, so people could get acquainted with the new measurement and could calibrate their own measuring devices. This is the only one on its original spot and one of two remaining in Paris.
In Leiden there is something similar, but with the Rhinelandic foot and the Rhinelandic rod, both pre-metric measurements.