Back to trivia. I was working at NIST this morning, so went over the see the US secondary standard of length, which was about 250' away. It was the primary standard from 1889 to 1960, when it was replaced by the wavelength of an Argon emission line (now obsolete, too, but not offically replaced yet). The sign say 'meter' (not 'metre') bar. It came from near Paris, International Bureau of Weights and Measures (its mame in English) and was probably a metre bar until it got to the US.