Answer
The answer is Paris. Sadi Carnot's only book, "Reflections on the Motive Power of Fire", was published in Paris, France, in 1824. It was a groundbreaking work in the field of thermodynamics and laid the foundation for the second law of thermodynamics. Carnot's book is considered a classic in the field of physics and has had a profound impact on the development of thermodynamics and engineering.