Carnot, Sadi

FRENCH PHYSICIST AND ENGINEER
1796–1832

Nicolas-Léonard-Sadi Carnot was born in 1796 in Paris. He is known as the father of thermodynamics. Originally a military engineer, he developed a keen interest in industry and especially the steam engine. He took a leave of absence from the military to devote more time to pursuing these interests.

Carnot published only one work in his lifetime—an essay that detailed the industrial, political, and economic importance of the steam engine. This essay also introduced the concept of the ideal steam engine and reported on the factors involved in the production of mechanical energy from heat. Carnot used the analogy of a waterfall to understand the ideal steam engine, positing that, as height and quantity of water determine the power of a waterfall, temperature drop and quantity of heat determine the power of a steam engine. Although his theory was not completely accurate, Carnot did make the correct observation that the power produced in a steam engine is dependent on a change in temperature.

Carnot died of cholera at a relatively young age, and this effectively ended the study of thermodynamics for almost two decades. It was not until 1850, when the English physicist William Thomson confirmed some of Carnot's theories, that his ideas on thermodynamics were more broadly applied. In fact, both the first and second laws of thermodynamics can be derived by extending Carnot's early theories.

see also Thermodynamics.

Lydia S. Scratch

Bibliography

Ihde, Aaron John (1964). The Development of Modern Chemistry. New York: Dover.

Internet Resources

Foundation of France. "Carnot Foundation." Available from <http://www.carnot.org>.

Carnot, (Marie François) Sadi (1837–94) French statesman, political leader, president of the Third Republic (1887–94). After quashing the anti-republican movement, he successfully defended the regime during the Panama Canal scandal (1892). He was stabbed to death by an Italian anarchist.