How and When Sadi Carnot invented Thermodynamics

[BaalChatzaf]

From Carnot's 1824 paper.  "Reflections on the Motive power of Heat". He lived during a marvelous time.  Steamboats,  Steam Driven Pumps and Steam Locomotives were just coming online.  60 years after Carnot wrote this paper another Marvelous Time was happening  -- electrification of the world.  The next such Marvelous Time was around 1950-1960  -- The computerization of the world.

 

Here it is.

That is the First and Second laws of Thermodynamics rolled into one.

The  production of motive power is then due  in
steam-engines not to an actual consumption of
caloric,  but  to  its transportation from a  warm body
body  to  a  cold body,  that  is,  to its re-establishment
of  equilibrium-an  equilibrium considered  as  de-
stroyed by any cause whatever, by chemical action
such  as  combustion, or by any other, We shall
see.  shortly  that  this principle is applicable to
any machine set in motion by heat. :

That is the First and Second laws of Thermodynamics rolled into one. Energy is conserved and heat moved from a warm body to a cold body.  This principle is general. It does not matter what medium a heat engine uses to transfer energy and derive  work from energy. 

Carnot did not quite grasp the nature of heat (he adhered to the theory of caloric or heat-fluid),  but he got conservation right and the fact that heat flow (spontaneously) from a warm body to a cold body (never the other way around spontaneously).