A marble ledge in the wall, under the arch at 36 rue de Vaugirard in Paris. A section divided into equal sectors and bounded by brass marks – the reference meter, one of the sixteen that were established in Paris at the end of the eighteenth century to get the citizens used to the new system of measurement. On April 7, 1795 in France, the law introducing the metric system of measurement came into force. 

The traditional units of measurement carried the familiar values of life to things and distances: step, finger, elbow… Different in every country, and not exactly identical there either. The lack of a standard, a basic unit for measuring distance, weight, volume, hindered trade and impeded industry. The French academicians developed a unified system of measurement for all countries in the second half of the 18th century. 

They took the meter as the basic unit – to determine the distance, the French astronomers calculated the distance from the North Pole to the equator via the meridian of Paris and divided it into 10 million parts. A square meter was taken as the unit of area, and a kilogram as the unit of mass. The system was originally designed as international, and therefore the new units did not coincide with the national ones in any country. The system convenience was also noted for its decimal form. In 1799, the result of the scientists’ work – the platinum prototypes of the meter and the kilogram – was approved and deposited in the Archives Nationales. 

The visible advantages did not immediately convince governments that it was necessary to switch to the new system. Napoleon said: “There is nothing more contrary to mind, memory, and consideration than what these scholars suggest. The good of the present generations has been sacrificed to abstractions and empty hopes, for to force the old nation to accept new units of weights and measures, it is necessary to revise all the administrative rules, all the calculations of industry. Such work intimidates the mind.” 

International metric standard used from 1889 to 1960

International metric standard used from 1889 to 1960

France was the first to adopt the new system, but it was not until 42 years after the law for its introduction was signed. In 1837, the Metric System was declared mandatory in all commercial transactions. Gradually it superseded local and national systems in other European countries. In 1875, 17 countries signed the Metric Convention that recognized the new system of measures as international and approved prototypes of the meter and kilogram for all countries. Since 1983, the length of the path that light travels in a time equal to 1/299,792,458 seconds has been taken as the reference for the meter. This definition does not change the meter length, but it is more accurate. 

There are only three countries in the world that have not officially adopted the Metric System – Liberia in west Africa, Myanmar in southeast Asia, and the United States. One of the reasons why the United States have not adopted the worldwide system is the pirates. In 1793, when the law on the new system introduction had not been issued yet, scientists in Paris decided to bring all units of measurement into a single system for the first time. The proposal was also sent to the American Congress. U.S. Secretary of State, Thomas Jefferson, welcomed the unification of the system of measurements; in order to begin using it, they needed standards – the standards were carried on a ship by botanist and aristocrat Joseph Dombey: a rod exactly one meter long and a copper cylinder weighing exactly one kilogram.

The ship was caught in a storm and went into the Caribbean Sea with the current. British corsairs seized the ship with the measurement standards, Joseph Dombey died in prison. All the property found on the ship was auctioned off.

A few years later France tried again to negotiate the unification of measurement systems, but the new Secretary of State, Edmund Randolph, was not interested in such a change. Today the U.S. uses the metric system of measurement in international trade.

Photo on the homepage: Tripguide