3 ms·

> to the best of their knowledge at the time I think it was actually extrapolated from a survey of the length of France. No idea how they did that extrapolati

• kergonath 5y ago
  Initially, yes. The story itself is quite fascinating, and the Wikipedia page on the metre is a good starting point. This was a hot topic during the 19th century as different improvements in the techniques and devices used to measure the Earth showed that the first measurements were imperfect, however good they had been at the time, and that the whole idea is not workable because the Earth is not a sphere. This lead to the formal definition of the metre as the length of a prototype in 1889.
  • usrusr 5y ago
    I imagine that the mental adjustment from sphere to almost but not quite a sphere must have been harder than a switch from flat earth to spherical. You just expect reality, if it matches a certain mathematical principle, to match perfectly.