The use of metric units for physical measurement was first introduced in France in 1795 and then adopted by 17 countries under an international convention in 1875. The metric system has since been accepted by all countries except the United States, Liberia and Burma (although the US was the first country to introduce a decimal currency, the dollar, in 1792). Metric units have been legal, but not obligatory, in the United Kingdom since 1896. The definition of metric units was most recently updated in the so-called système international d’unités (SI), agreed by the Conference générale des poids et mesures (CGPM), in 1960. Five years later, the British government announced that it would replace imperial units with the SI system over coming decades. Ireland began a similar conversion in the 1970s, a process it completed in 2005.
In 1979, the Council of Ministers sought to standardise in law all units of measurement within the European Community on the basis of the SI agreement, with a transitional period for other units until 1989 – a deadline subsequently extended to 1999 and 2009. During this period, traders in Britain would still be able to display measurements in both imperial and metric units, but not in imperial units alone. Public resistance to the move proved more entrenched than expected, and UK was granted specific, permanent exemptions for use of the mile and yard in road markings, and for the pint for beer and milk. A number of high-profile court cases involving ‘metric martyrs’, who insisted on displaying goods other than beer and milk exclusively in imperial units, kept the issue live. In May 2007, the European Commission announced that it would no longer seek to enforce metric-only labelling on packaged goods, so allowing dual metric-imperial marking to continue indefinitely.
Copyright: Anthony Teasdale, 2012
Citation: The Penguin Companion to European Union (2012), additional website entry