The history of the metric system began during the 17th and 18th century when Europe was experiencing a wave of intellectuals and philosophers called the Age of Enlightenment. The intellectuals at the time used length and weight derived from and inspired by nature along with their fractions and decimal multiples. Soon, it became the standard of both Europe and France.
With time, the system was updated and reached a point where it was adopted by the entire world. To understand how the system works, we ought to re-visit history and discover where and how it all began.
Age of Enlightenment
The metric system’s history dates back to the early ninth century when much of France was a part of the Holy Roman Empire but later became a part of France itself. At the time, Emperor Charlemagne standardized the units of measure. He worked hard to standardize the units for mass and length throughout his empire.
However, when the empire disintegrated into separate nations, the standards diverged as well. The Magna Carta in England stated that there should be standard measures for corn, ale, and wine throughout the kingdom. Similarly, there should be a standard width of russet, dyed cloth, and haberject, etc.
The metric system history timeline also highlights that during the early medieval era, Europe used Roman numerals to represent numbers. However, the Arabs used the Hindu numeral system. Then, Fibonacci published his book Liber Abaci in 1202 introducing the concept of positional notation in Europe.
This was a time when rational and irrational numbers were argued. As a result, Simon Stevin stepped up and generalized the use of the decimal system in Europe. The year 1586, saw Stevin publishing a small pamphlet called “the tenth”, which historians credit for serving as the basis of modern notation for decimal fractions.
Body Measures and Artefacts
Since the time of Emperor Charlemagne, the standard of length was the measure of the body that ran from fingertip to fingertip of the outstretched arms of a large man. At the time, an iron bar, which was considered to be the most durable substance in the Middle Ages was used to make an artifact to represent the standard.
However, with time, the problems of non-reproducible artifacts became evident as they were either stolen, rusted or simply lost at times. When a new royal standard had to be cast, it was different from the old one and therefore, the replicas of both old and new ones popped up and were used. The artifact was called “toise” and existed throughout the 18th century.
Clocks and Pendulums
Dutch Scientist Christiaan Huygens in 1656 invented and introduced the pendulum clock featuring a pendulum that marked the seconds. This proposed the idea that its length should be used as a standard unit. But soon, it was realized that the length of the pendulum varied in different locations.
In 1670, Gabriel Mouton, a French astronomer, and abbot published the book “Observations of the apparent diameters of the Sun and Moon”. He suggested that the scientists use a decimal system of measurement of length for international communication. The system would be based on the dimensions of the earth.
Huygens’ work along with the likes of Mouton attracted interest and helped contribute to the determination of a standard unit of length.
Late 18th Century
By the 18th century, it was evident that the metric system order needed to be finalized and implemented especially between nations who traded scientific ideas. For instance, Spain had aligned their units of measurement with the royal units of France, while Peter the Great aligned the units of measure with those of England.
In 1783, British inventor James Watt after experiencing complications and difficulties communicating with German scientists called for a global decimal measurement system. Several years later, the French sent a proposal to Britain and the United States.
The proposal called for developing and establishing a uniform measure of length but was turned down in the British Parliament and United States Congress. For nearly 200 years, the main countries involved in the development of the metric system failed to come up with the appropriate standards.
Implementation in Revolutionary France
The Units of Weight and Length
The French Academy of Sciences in 1790, developed a bench of five leading French scientists to investigate measures and weights. The panel for almost an entire year conducted different experiments and put forward different recommendations regarding a new system of weights and measures.
One proposal stated that the unit of length should be based on a fractional arc of a quadrant of the Earth’s meridian and the unit of weight should be that of a cube of water whose dimension was a decimal fraction of the unit of length. In 1791, the French Assembly had accepted the proposals.
After 1792, “gramme”, which despite being too small for practical realization for many purposes was adopted, and a new prefix “kilo” was added from “kilogramme”. The year 1795 saw the French law define the metric system including six new decimal units such as litre, meter, gramme, franc, are, and stere.
By the late 1860s, it was felt that better metric standards should be introduced to keep pace with scientific advances. In 1875, a metric system review was done, which was basically called the Convention of the Meter. It was an international agreement to set up well-defined metric standards for length and mass.
The agreement was commonly called the “Treaty of the Meter” in the United States and was signed by 17 countries including America itself. As a result, the internationally adopted metric standards in 1893 still serve as the fundamental measurement standards of the United States.
By 1900, a total of 35 countries had officially adopted and accepted the metric system. In 1960, the signatory nations to the Convention of the Meter adopted simplification of the system along with extensive revision. Seven units, ampere, kelvin, meter, kilogram, mole, candela, and the second were established as the system’s base unit. This was the birth of the modern metric system.
The introduction and development of the metric system was crucial. What started with the meter formed the basis of modern economies and globalization. Today, the capabilities and reach of the metric system are unlimited. It enables high-precision engineering and plays an important role in science and research. And, while scientists and researchers compete and push for refining the existing and introducing newer concepts, the overall system is destined to improve with time.