Historical standards, metre and yard. The two standards here are the International Prototype Metre (iridium-platinum, standard from 1889 to 1960) and the Imperial Standard Yard (officially recognised in 1855). The former was established in France as part of the basis of the international metric system. The latter was established in the UK as part of the imperial system of weights and measures. The UK's replacement of imperial units with the metric system began in 1965, though the use of yards and miles remains widespread in the 21st century. Photographed at the National Physical Laboratory, Teddington, UK.