Mesures usuelles

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Mesures usuelles (French pronunciation:  [məzyʁ yzɥɛl] , customary measurements) were a French system of measurement introduced by Napoleon I in 1812 to act as compromise between the metric system and traditional measurements. The system was restricted to use in the retail industry and continued in use until 1840, when the laws of measurement from the 1795 and 1799 were reinstituted. [1]

Units of measurement in France

France has a unique history of units of measurement due to the radical decision to invent and adopt the metric system after the French Revolution.

Metric system Decimal system of units of measurement

The metric system is an internationally recognised decimalised system of measurement. It is in widespread use, and where it is adopted, it is the only or most common system of weights and measures. It is now known as the International System of Units (SI). It is used to measure everyday things such as the mass of a sack of flour, the height of a person, the speed of a car, and the volume of fuel in its tank. It is also used in science, industry and trade.

Units of measurement in France before the French Revolution

Before the French Revolution, which started in 1789, French units of measurement were based on the Carolingian system, introduced by the first Holy Roman Emperor Charlemagne (800 – 814 AD) which in turn were based on ancient Roman measures. Charlemagne brought a consistent system of measures across the entire empire. However, after his death, the empire fragmented and many rulers introduced their own variants of the units of measure.


Rationale behind the new system

The ordinary measures were introduced by Napoleon I in 1812 Napoleon Groot.jpg
The ordinary measures were introduced by Napoleon I in 1812

In the five years immediately before the French First Republic introduced the metric system, every effort was made to make the citizens aware of the upcoming changes and to prepare them for it. [2] The administration distributed tens of thousands of educational pamphlets, private enterprise produced educational games, guides, almanacs and conversion aids, and metre standards were built into the walls of prominent buildings around Paris. [2] The introduction was phased by district over the next few years, with Paris being the first district to change. The government also realised that the people would need metre rulers, but they had only provided 25,000 of the 500,000 rulers needed in Paris as late as one month after the metre became the sole legal unit of measure. [2] To compensate, the government introduced incentives for the mass-production of rulers. Paris police reported widespread flouting of the requirement for merchants to use only the metric system. [2] Where the new system was in use, it was abused, with shopkeepers taking the opportunity to round prices up and to give smaller measures. [2]

French First Republic Republic governing France, 1792–1804

In the history of France, the First Republic, officially the French Republic, was founded on 22 September 1792 during the French Revolution. The First Republic lasted until the declaration of the First Empire in 1804 under Napoleon, although the form of the government changed several times. This period was characterized by the fall of the monarchy, the establishment of the National Convention and the Reign of Terror, the Thermidorian Reaction and the founding of the Directory, and, finally, the creation of the Consulate and Napoleon's rise to power.

The Mesures usuelles were abolished by Louis-Philippe in 1839 Louis-Philippe-France.png
The Mesures usuelles were abolished by Louis-Philippe in 1839

Napoleon I, the French Emperor, disliked the inconvenience of surrendering the high factorability of traditional measures in the name of decimalisation, and recognized the difficulty of getting it accepted by the populace. [3] Under the décret impérial du 12 février 1812 (imperial decree of 12 February 1812), he introduced a new system of measurement, the mesures usuelles or "customary measures", for use in small retail businesses. However, all government, legal and similar works still had to use the metric system and the metric system continued to be taught at all levels of education. [4] [5]

Factorization decomposition of an object into a product of other objects

In mathematics, factorization or factoring consists of writing a number or another mathematical object as a product of several factors, usually smaller or simpler objects of the same kind. For example, 3 × 5 is a factorization of the integer 15, and (x – 2)(x + 2) is a factorization of the polynomial x2 – 4.

Decimal Numeral system with ten as its base

The decimal numeral system is the standard system for denoting integer and non-integer numbers. It is the extension to non-integer numbers of the Hindu–Arabic numeral system. The way of denoting numbers in the decimal system is often referred to as decimal notation.

The prototypes of the metric unit, the kilogram and the metre, enabled an immediate standardization of measurement over the whole country, replacing the varying legal measures in different parts of the country, and even more across the whole of Europe. The new livre (known as the livre métrique) was defined as five hundred grams, and the new toise (toise métrique) was defined as two metres. Products could be sold in shops under the old names and with the old relationships to one another, but with slightly different absolute sizes. This series of measurements was called mesures usuelles.

Prototype early sample or model built to test a concept or process

A prototype is an early sample, model, or release of a product built to test a concept or process. It is a term used in a variety of contexts, including semantics, design, electronics, and software programming. A prototype is generally used to evaluate a new design to enhance precision by system analysts and users. Prototyping serves to provide specifications for a real, working system rather than a theoretical one. In some design workflow models, creating a prototype is the step between the formalization and the evaluation of an idea.

Kilogram SI unit of mass

The kilogram is the base unit of mass in the metric system, formally the International System of Units (SI), having the unit symbol kg. It is a widely used measure in science, engineering, and commerce worldwide, and is often simply called a kilo in everyday speech.

Metre SI unit of length

The metre or meter is the base unit of length in the International System of Units (SI). The SI unit symbol is m. The metre is defined as the length of the path travelled by light in a vacuum in 1/299,792,458 of a second.

Napoleon's decree was revoked during the reign of Louis Philippe by the loi du 4 juillet 1837 (law of 4 July 1837). This took effect on 1 January 1840, and reinstated the original metric system, thus bringing the system of mesures usuelles to an end. [4]

Permitted units

The law authorised the following units of measure: [6]

The mesures usuelles did not include any units of length greater than the toise - the myriamètre (10 km) remaining in use throughout this period. [8]

See also

Related Research Articles


Metrication or metrification is the act or process of converting the system of measurement traditionally used in a country to the metric system. Worldwide, there has been a process of nations transitioning from their various local and traditional units of measurement, to the metric system. This process first began in France during the 1790s and has continued extensively world-wide over the following two centuries, but the metric system has not been fully adopted in all countries and sectors.

Metre Convention 1875 international treaty

The Metre Convention, also known as the Treaty of the Metre, is an international treaty that was signed in Paris on 20 May 1875 by representatives of 17 nations. The treaty created the International Bureau of Weights and Measures (BIPM), an intergovernmental organization under the authority of the General Conference on Weights and Measures (CGPM) and the supervision of the International Committee for Weights and Measures (CIPM), that coordinates international metrology and the development of the metric system.

United States customary units are a system of measurements commonly used in the United States. The United States customary system developed from English units which were in use in the British Empire before the U.S. became an independent country. However, the United Kingdom's system of measures was overhauled in 1824 to create the imperial system, changing the definitions of some units. Therefore, while many U.S. units are essentially similar to their Imperial counterparts, there are significant differences between the systems.

Gram Unit of mass 1/1000th of a kilogram

The gram is a metric system unit of mass.

The foot is a unit of length in the imperial and US customary systems of measurement. Since the International Yard and Pound Agreement of 1959, one foot is defined as 0.3048 meter exactly. In customary and imperial units, the foot comprises 12 inches and three feet compose a yard.


Myria- (symbol my) is a now obsolete decimal metric prefix denoting a factor of 104 (ten thousand). It originates from the Greek μύριοι (mýrioi) (myriad). The prefix was part of the original metric system adopted by France in 1795, but was not adopted when the SI prefixes were internationally adopted by the 11th CGPM conference in 1960.

The "Plan for Establishing Uniformity in the Coinage, Weights, and Measures of the United States" was a report submitted to the U.S. House of Representatives on July 13, 1790, by Secretary of State Thomas Jefferson.

A system of measurement is a collection of units of measurement and rules relating them to each other. Systems of measurement have historically been important, regulated and defined for the purposes of science and commerce. Systems of measurement in use include the International System of Units (SI), the modern form of the metric system, the imperial system, and United States customary units.

The following systems arose from earlier systems, and in many cases utilise parts of much older systems. For the most part they were used to varying degrees in the Middle Ages and surrounding time periods. Some of these systems found their way into later systems, such as the Imperial system and even SI. There were several types to measure that is

Gabriel Mouton was a French abbot and scientist. He was a doctor of theology from Lyon, but was also interested in mathematics and astronomy. His 1670 book, the Observationes diametrorum solis et lunae apparentium, proposed a natural standard of length based on the circumference of the Earth, and was decimally divided. It was influential in the adoption of the metric system in 1799.

Dutch units of measurement

The Dutch units of measurement used today are those of the metric system. Before the 19th century, a wide variety of different weights and measures were used by the various Dutch towns and provinces. Despite the country's small size, there was a lack of uniformity. During the Dutch Golden Age, these weights and measures accompanied the Dutch to the farthest corners of their colonial empire, including South Africa, New Amsterdam and the Dutch East Indies. Units of weight included the pond, ons and last. There was also an apothecaries' system of weights. The mijl and roede were measurements of distance. Smaller distances were measured in units based on parts of the body – the el, the voet, the palm and the duim. Area was measured by the morgen, hont, roede and voet. Units of volume included the okshoofd, aam, anker, stoop, and mingel. At the start of the 19th century the Dutch adopted a unified metric system, but it was based on a modified version of the metric system, different from the system used today. In 1869, this was realigned with the international metric system. These old units of measurement have disappeared, but they remain a colourful legacy of the Netherlands' maritime and commercial importance and survive today in a number of Dutch sayings and expressions.

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Comparison of the imperial and US customary measurement systems

Both the imperial and United States customary systems of measurement derive from earlier English systems used in the Middle Ages, that were the result of a combination of the local Anglo-Saxon units inherited from German tribes and Roman units brought by William the Conqueror after the Norman Conquest of England in 1066.

A toise is a unit of measure for length, area and volume originating in pre-revolutionary France. In North America, it was used in colonial French establishments in early New France, French Louisiana (Louisiane), and Quebec. The related toesa was used in Portugal, Brazil and other parts of the Portuguese Empire until the adoption of the Metric system.

History of the metre

The history of the metre starts with the scientific revolution that began with Nicolaus Copernicus's work in 1543. Increasingly accurate measurements were required, and scientists looked for measures that were universal and could be based on natural phenomena rather than royal decree or physical prototypes. Rather than the various complex systems of subdivision in use, they also preferred a decimal system to ease their calculations.

A number of units of measurement were used in Switzerland to measure length, mass, etc. Metric system was optional in 1868, and has been compulsory since 1877.


The klafter is an historical unit of length, volume and area that was used in Central Europe.


  1. "History of measurement". Métrologie française. Retrieved 2011-02-06.
  2. 1 2 3 4 5 Alder, Ken (2002). The Measure of all Things - The Seven-Year-Odyssey that Transformed the World. London: Abacus. ISBN   0-349-11507-9.
  3. Napoleon I (19 December 1809). "Letter to Général Clarke, duc de Feltre". Correspondance de Napoléon Ier: publiée par ordre de l'empereur Napoléon III. Retrieved 2011-02-10. Je me moque des divisions décimales [I don't care about decimal divisions]
  4. 1 2 Denis Février. "Un historique du mètre" (in French). Ministère de l'Economie, des Finances et de l'Industrie. Retrieved 2011-03-10.
  5. For example the engineering textbook, Stéphane Flachat (1835). Traité élémentaire de méchanique industrielle. Paris. Retrieved 2011-02-17.
  6. Hallock, William; Wade, Herbert T (1906). "Outlines of the evolution of weights and measures and the metric system". London: The Macmillan Company. pp. 66–69.
  7. Thierry Sabot (1 October 2000). "Les poids et mesures sous l'Ancien Régime" [The weights and measures of the Ancien Régime] (in French). histoire-genealogie. Retrieved 2011-02-10.
  8. 1 2 Appell, Wolfgang (2009-09-16) [2002]. "Königreich Frankreich" [Kingdom of France]. Amtliche Maßeinheiten in Europa 1842 [Official units of measure in Europe 1842] (in German). Archived from the original on 2011-10-05. Retrieved 2011-02-10.. (Website based on Alte Meß- und Währungssysteme aus dem deutschen Sprachgebiet, ISBN   3-7686-1036-5.)