Jacques Alexandre César Charles, born November 12, 1746 in Beaugency, France, was an important chemist and physicist who studied gases. He developed the theory that bears his name, Charles Law.
As a child, his education had little science. He learned basic math and did few science experiments.
Younger, he went to Paris and worked at the Secretariat of Finance. In 1779 Benjamin Franklin visited Paris as ambassador for the newly created United States. Cahrles learned about Franklin's science experiments. He was impressed and began to study experimental physics thereafter. He was a chemist, physicist, aeronautic, mathematician and inventor.
After a year and a half of studies, in 1781 he began giving public lectures on the things he had learned. Around 1787, Charles developed his theory, Charles Law. He did not publish it but Gay-Lussac published it fifteen years later. His works were based on the study of gases. It has redesigned the way hot air balloons were built. Invented the valve line among other equipment for gas conditioning.
But his best-known invention, no doubt, was Charles's Law, which states that the constant volume, the pressure of a given mass of gas is directly proportional to its absolute, ie constant, temperature. This is one of the perfect gas or ideal gas laws. It determined the density of water at various temperatures.
Before discovering his law, he was the first to come up with the idea of using hydrogen to fill aerostatic balloons. Until then hot air balloons were used. Hydrogen was obtained by decomposition of water by sulfuric acid in the presence of iron.
On August 27, 1783, along with his brother Robert, Charles put his idea into practice and flew over Paris. It reached about 1600m of altitude. It covered approximately 20km. The feat startled the observers from the noise of the gas escaping from the balloon.
Charles was appointed resident member of the Academie des Sciences on November 20, 1785. He was a professor at the Conservatory of Arts and Careers for Experimental Physics. He was also a librarian and president of experimental physics in 1816. Charles died on April 7, 1823.