Great scene of a great movie! There was not just a bad and confusing order, from above, where the Russian positions were clear, to the cavalry below, from where they were not. Lots of personal feuds and issues between the characters, developed earlier in the movie, and a lot based on hstorical facts, made it even more complicated.
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And on March 30th 1791, the first definition of the metre was established, by the French Academy of Sciences, as one ten millionth of the distance between the equator and the North Pole along the Meridian of Paris.