The French revolutionary government declares the decimal-based metric system to be the official system of weights and measures on April 7, 1795. The system was developed by the Paris Academy of Sciences as part of the Revolution's move away from old royal traditions.
The metric system was based on natural constants (like the Earth's circumference for the meter) and decimal (base-10) multiples, simplifying calculations. It defined the meter (length), gram (mass), liter (volume), etc. Although officially decreed in 1795, public resistance and the complexity of its implementation slowed down its acceptance and implementation. It was made compulsory in 1840. The metric system went on to became the global standard, evolving into the International System of Units (SI).
