Sadi Carnot

Overview

Nicolas Léonard Sadi Carnot was a French military engineer who published one book, at twenty-eight, and died of cholera at thirty-six. The book asked a practical question about steam engines and answered it with a general result: the greatest possible fraction of heat convertible into work depends only on the temperatures of the hot and cold reservoirs, not on the working substance or the design of the machine. He reached this using the caloric theory of heat, which was later abandoned, yet the conclusion survived because it does not depend on that assumption. Clausius and Kelvin built the second law of thermodynamics directly on his argument. The book is short and non-mathematical for most of its length, and it is the best single starting text in the thermodynamics chain.

Where to start reading

• Reflections on the Motive Power of Fire 1824

  The founding text of thermodynamics, arguing that an engine's maximum efficiency is fixed by the two temperatures it works between. The Gutenberg edition is the English translation, printed together with related papers by Kelvin.

  Read it in the library

Part of

• Thermodynamics

Sources

1. Nicolas Léonard Sadi Carnot English Wikipedia
2. Sadi Carnot Britannica
3. Carnot heat engine English Wikipedia