Benoit-Pierre-Émile Clapeyron was an important physicist and civil engineer, born in France on February 26, 1799. He studied thermodynamics and gases within chemistry. He attended the École Polytechnique de Paris, where he joined in 1816. Two years later, he assumed the position of Mining Engineer, where he also taught.

In 1820, he went to Russia with his friend and classmate Gabriel Lamé. Both taught pure and applied mathematics at the École des Travaux Publics in St. Petersburg. This school had had a major boost since 1809, when Emperor Alexander I created a corps of engineers responsible for studying roads, bridges, and weapons.

While in Russia, he wrote several articles with Gabriel Lamé. These articles were mainly published in the Journal of Communication Voices of Saint-Pétersbourg, the Journal of Civil Genius and the Bulletin Ferussac. In 1830, they were forced to leave the country because of the Revolution. Clapeyron and Lamé entered the railroad construction business early (1823).

In 1833, a large amount of money was released for a study of the various problems that were encountered in railroad construction. This even included an exchange between American and English engineers. Clapeyron then came up with the idea of ​​the road linking Paris with St. Germain, but while waiting for the money, he worked as a teacher at St. Etienne at the École de Mineurs.

In 1835 when the money was released, the two friends were placed responsible for the direction of the work. Clapeyron specializes in the development of steam locomotives. In 1836, he went to England to order the locomotives that were to operate on the difficult and long journey between Paris and St. Germain. When the direction of the project shifted to Robert Stephenson, the locomotives were still manufactured based on Clapeyron's design.

He continued to investigate the phenomena related to steam engines. Even his best work is not the most recognized, where he wrote about the possible valve settings for a steam engine. From 1844 onwards, Clapeyron taught at the Ecole des Ponts et Chaussés, where he gave a course on steam engines.

His main contribution to chemistry was in thermodynamics. He formulated the perfect gas equation, which is the well-known Clapeyron equation and also the perfect gas constant R. This scientist's study was an application of the Sadi Carnot principle, developed by Carnot (1824).

Carnot's works were not accepted at the time. When Clapeyron's study was published, which transformed Carnot's verbal analysis into a symbolism of calculus, the scientific community had greater acceptance of Carnot's Theory. Clapeyron died on January 28, 1864.