Nicolas Carnot, a mechanical engineer in the French Army, as well as a military scientist and physicist, is often labeled as the “father of thermodynamics.” At the age of 27 Carnot published a book, Reflections on the Motive Power of Fire (Paris, 1824). In his book Carnot wrote the first “successful theory of the maximum efficiency of heat engines,” as well as outlining the idea of the internal combustion engine. In doing so, he began the discipline of thermodynamics. Carnot’s writing attracted little attention during his lifetime; however, it was later the foundation for the second law of thermodynamics and the definition of entropy, which were developed by Rudolf Clausius and Lord Kelvin. 

Nicolas Carnot. (Image:

Based on technical issues, such as improving the performance of the steam engine, Carnot’s work is the foundation for such modern technology as the automobile or jet engine. However,

Carnot never attempted to build an internal combustion engine.

The “Ideal Carnot Cycle.” (Image:

Lenoir and his engine

About 30 years after Carnot’s book was published, gaseous fuels were commercially available. That led a French inventor to develop the first practical and commercially successful internal combustion engine. 

Today is the 121st anniversary of the death of Jean Joseph Étienne Lenoir, the inventor of the internal combustion engine. Lenoir was born in Belgium and emigrated to France during the 1850s. He died near Paris at the age of 78.

Lenoir built a two-stroke, one-cylinder internal combustion engine in 1859. He used a converted steam engine with slide valves to take in a mixture of air and coal gas as well as to discharge the engine’s exhaust. Lenoir’s engine used a battery to supply an electrical charge to ignite the gas after it was drawn into the cylinder.

Although only about 4% efficient in regard to fuel consumption, Lenoir’s engine was durable and mostly smooth-running. He applied to the Paris-based Conservatoire National Des Arts Et Métiers for a patent; the organization awarded him a patent in 1860 for his “air motor expanded by gas combustion.”

By 1865 more than 400 of Lenoir’s engines were being used in France and more than 1,000 were in use in Great Britain. His early engines were primarily used for low-power activities such as running water pumps and printing presses. While inefficient compared to later models, Lenoir’s engines were very durable – some were still running and in very good condition after more than 20 years of continuous operation.  

An illustration of Lenoir’s internal combustion engine and of the inventor. (Image:

Lenoir’s automobile

After receiving his patent for the engine he created, Lenoir turned his attention to powering a vehicle with an internal combustion engine. He built what is generally recognized as the first automobile powered by an internal combustion engine in 1862. Adapting his engine to run on liquid fuel, the vehicle’s first outing was a six-mile trip that took more than two hours.

Lenoir improved his engine, and in 1863 Lenoir incorporated a different version of his internal combustion engine on a three-wheeled carriage that he built. Named the Hippomobile, it had a wagon body fitted on top of a tricycle. It completed an 11-mile round-trip between Paris and Joinville-le-Pont in just under three hours.

However, his two-cycle engines were too small and inefficient to successfully power a carriage at speed.

Lenoir at the controls of a three-wheeled vehicle powered by an internal combustion engine. (Photo: curiokids)

Lenoir’s other inventions

Lenoir invented several other useful devices. Examples include the spark plug for automobile ignition systems. His invention is essentially the same as those used in cars today. He also invented white tin oxide without enamel in 1847, a revolutionary procedure for electroplating in 1851, an electric brake for trains in 1855, an electric motor in 1856, a mechanical kneader in 1857, a controller for dynamos in 1859, an autografico telegraph in 1865, a motorboat powered by an internal combustion engine in 1886, and a method of tanning leather with ozone.

An illustration of an early wheeled vehicle powered by Lenoir’s internal combustion engine. (Illustration: Le Monde Illustre)