#276 Reflections on the Motive Power of Fire and on Machines Fitted to Develop That Power


Provided the first general theory of heat engines, and explanation of the efficiency of high pressure steam engines.

Nicholas Sadi Carnot's Reflections on the Motive Power of Fire and on Machines Fitted to Develop that Power, published in France in 1824, was among the earliest attempts to understand and explain the theory of heat engines. Essentially, Carnot sought to answer two critical questions: whether using a substance besides steam might improve the performance of heat engines and, whether heat engines could be 100 percent efficient - converting all received heat into useful work.

He concluded that substance did not matter, because higher efficiency in heat engines is achieved when there is a greater difference between the temperature at which heat is supplied to a heat engine and the temperature at which it is rejected or discharged from that machine. 

The book has had a lasting influence in the field by introducing a number of principles that became known as the Carnot Cycle, the Carnot heat engine, Carnot's theorem, and laid the foundations for Thermodynamics.

Mechanical Engineers have utilized his principles in thermodynamics to advance the efficiency of heat engines in power plants, automobile engines, jet engines, among other types, by employing greater temperature differences.


Landmark Location

This landmark was approved as part of ASME's Virtual Landmark Program


Landmark recognition date

Spring 2021

Download Brochure

You are now leaving ASME.org