What is Metre Convention?
[[File:Metre Convention Signatories.svg|thumb|350px|Metre Convention signatories: {{Legend|red|Member States}}{{Legend|LightPink|Associate Member States}}]] The '''Metre Convention''' is the [[treaty]] that set up the [[International Bureau of Weights and Measures]] (BIPM). The BIPM is an inter-governmental organization that is responsible for harmonizing [[system of measurement|systems of measurement]] across the world. The treaty was first made in 1875 between 17 countries. The member countries agreed to share the costs of running a laboratory on [[Neutral|neutral territory]]. The international prototype [[metre]] and the international prototype [[kilogram]] would be kept at the laboratory. Member state's national prototype metres and kilograms would be compared with the international prototypes at regular intervals. Member states would have regular meetings to discuss developments in measurement technology. In 1921 the treaty was extended to cover [[electricity|electrical]] and all other [[matter|physical]] measurements. This enabled the BIPM to published the standards for the [[International System of Units]] (SI). Under SI, [[Unit of measurement|units of measurements]] that are used in [[science]] and [[engineering]] were defined in a [[logical]] manner. The rules for SI also standardized the way in which [[Physical quantity|physical quantities]] are written. In 2014 the BIPM had 55 member countries. == Before the treaty == The metric system was developed in France in the 1790s. The length of the metre was made to be one ten millionth of the distance between the [[North Pole]] and the [[equator]]. Between 1791 and 1798 the French men Delambre (a [[mathematician]] and [[astronomer]]) and Méchain (an astronomer) measured the distance between [[Dunkirk]] and [[Barcelona]]. The measurements were used to make a metal bar exactly 443.296 ''lignes'' long (the ''ligne'' is an old French unit of length equal to one twelfth of a French inch). The bar would be used as a [[standard]] for the metre. The bar was late