Metrication

The process of metrication is typically initiated and overseen by a country's government, generally motivated by the necessity of establishing a uniform measurement system for effective international cooperation in fields like trade and science.

[14] Throughout the 1990s, the European Commission helped accelerate the metrication process for member states, for the implemented the Units of Measure Directive to promote trade.

[20] After the joining of canton of Geneva to Switzerland in 1815, Guillaume Henri Dufour published the first Swiss official map for which the metre was adopted as unit of length.

In addition to the Exposition Universelle and the second Statistical Congress held in Paris, an International Association for obtaining a uniform decimal system of measures, weights, and coins was created there in 1855.

[37][38] During the nineteenth century the metric system of weights and measures proved a convenient political compromise during the unification processes in the Netherlands, Germany and Italy.

During the Napoleonic era, some of the German states moved to reform their systems of measurement using the prototype metre and kilogram as the basis of the new units.

In 1832, Carl Friedrich Gauss studied the Earth's magnetic field and proposed adding the second to the basic units of the metre and the kilogram in the form of the CGS system (centimetre, gram, second).

In 1836, he founded the Magnetischer Verein, the first international scientific association, in collaboration with Alexander von Humboldt and Wilhelm Edouard Weber.

The foundation of the Magnetischer Verein would be followed by that of the Central European Arc Measurement (German: Mitteleuropäische Gradmessung) on the initiative of Johann Jacob Baeyer in 1863, and by that of the International Meteorological Organisation whose second president, the Swiss meteorologist and physicist, Heinrich von Wild represented Russia at the International Committee for Weights and Measures (CIPM).

[54][55][56] In 1867, the European Arc Measurement (German: Europäische Gradmessung) called for the creation of a new, international prototype metre (IPM) and the arrangement of a system where national standards could be compared with it.

The French government gave practical support to the creation of an International Metre Commission, which met in Paris in 1870 and again in 1872 with the participation of about thirty countries.

[59] The Netherlands (as the revolutionary Batavian Republic) began to use the metric system from 1799 but, as with its co-revolutionaries in France, encountered numerous practical difficulties.

Under the (Dutch) Weights and Measures Act of 21 August 1816 and the Royal decree of 27 March 1817 (Koningklijk besluit van den 27 Maart 1817), the newly formed Kingdom of the Netherlands abandoned the mesures usuelles in favour of the "Dutch" metric system (Nederlands metrisch stelsel) in which metric units were simply given the names of units of measure that were then in use: for instance the ons (ounce) was defined as 100 g.[60] In 1875, Norway was the first country to ratify the metre convention, and it was seen as an important step towards Norwegian independence.

In 1867 at the second general conference of the geodetic association held in Berlin, the question of an international standard unit of length was discussed in order to combine the measurements made in different countries to determine the size and shape of the Earth.

These prototypes defined the metre right up until 1960.In 1801, the Helvetic Republic at the instigation of Johann Georg Tralles promulgated a law introducing the metric system.

In 1835, twelve cantons of the Swiss Plateau and the north-east adopted a concordat based on the federal foot (exactly 0.3 m) which entered into force in 1836.

In 1875, the responsibility for weights and measures was transferred back from the cantons to the Confederation, and Switzerland (represented by Adolphe Hirsch) joined the Metre Convention.

During the next eighty years a number of Parliamentary select committees recommended the adoption of the metric system, each with a greater degree of urgency, but Parliament prevaricated.

[citation needed] In 1805 a Swiss geodesist Ferdinand Rudolph Hassler brought copies of the French metre and kilogram to the United States.

The bill, which was permissive rather than mandatory in nature, defined the metric system in terms of customary units rather than with reference to the international prototype metre and kilogram.

This led to the Mendenhall Order which redefined the customary units by referring to the national metric prototypes, but used the conversion factors of the 1866 act.

In that country, the square foot is still widespread for commercial and residential advertisements and partially in construction because of the close trade relations with the United States.

The railways of Canada such as the Canadian National and Canadian Pacific as well as commuter rail services continue to measure their trackage in miles and speed limits in miles per hour because they also operate in the United States (although urban railways including subways and light rail have adopted kilometres and kilometres per hour).

Resistance to metrication in post-revolutionary France convinced Napoleon to revert to mesures usuelles (usual measures), and, to some extent, the names remain throughout Europe.

In Sweden and Norway, a mil (Scandinavian mile) is informally equal to 10 km, and this has continued to be the predominantly used unit in conversation when referring to geographical distances.

In China, the jin now has a value of 500 g and the liang is 50 g. Surveys are performed by various interest groups or the government to determine the degree to which ordinary people change to using metric in their daily lives.

[158] In 1965, with lobbying from British industries and the prospects of joining the Common Market, the government set a 10-year target for full conversion, and created the Metrication Board in 1969.

[162] Imperial units remain in common everyday use for human body measurements, in particular stones and pounds for weight, and feet and inches for height.

[163] Heating, air conditioning, and gas cooking appliances occasionally display power in British thermal units per hour (BTU/h).

NASA and other organisations worked in metric units, but one subcontractor, Lockheed Martin, provided thruster performance data to the team in pound force-seconds instead of newton-seconds.