<P> British scientists, philosophers and engineers have been at the forefront of the development of metrication--in 1668 John Wilkins first proposed a coherent system of units of measure, in 1861 a committee of the British Association for Advancement of Science (BAAS), including William Thomson (later Lord Kelvin), James Clerk Maxwell and Joule among its members, defined various electrical units in terms of metric rather than imperial units, and in the 1870s Johnson, Matthey & Co manufactured the international prototype metre and kilogram . </P> <P> When James VI of Scotland inherited the English throne in 1603, England and Scotland had different systems of measure . Superficially the English and the Scots units of measure were similar--many had the same names--but there were differences in their sizes: in particular the Scots pint and gallon were more than twice the size of their English counterparts . In 1707, under the Act of Union, the Parliaments of England and Scotland were merged and the English units of measurement became the standard for the whole new Kingdom of Great Britain . The practical effect of this was that both systems were used in Scotland, and the Scottish measures remained in common use until the Weights and Measures Act 1824 outlawed them . </P> <P> This period marked the Age of Enlightenment, when people started using the power of reason to reform society and advance knowledge . Britons played their role in the realm of measurement, laying down practical and philosophical foundations for a decimal system of measurement which were ultimately to provide the building blocks of the metric system . </P> <P> One of the earliest decimal measuring devices, developed in 1620 by the English clergyman and mathematician Edmund Gunter, introduced two new units of measure--the chain and the link--and a new measuring device: Gunter's chain . Gunter's chain was one chain (one tenth of a furlong) in length and consisted of 100 links, making each link 0.001 furlongs . The decimal nature of these units and of the device made it easy to calculate the area of a rectangle of land in acres and decimal fractions of an acre . </P>

When did england move to the metric system