"But 1812's dark season came And metric hearts were sore.."
Today 195 years ago, 1812 February 12, was a day of infamy in the history of metrology. On that day Napoleon came up with his Imperial Decree on Weights and Measures. The decree stated that the system established under the metric laws would not be changed, but instruments of weight and measurement were to be adopted, geared to the needs of the people. These 'instruments' were more than that: it was the return to the weights and measures of Paris for use in the retail shops. The existence of the metric system itself was at stake. Then followed a struggle that would last for 25 years, until in 1837 France passed the law that made her metric for good from January 1840. Suppose that this had not happened, I think that the USA would be a fully metric nation today.
