19th century in science Carnot captured some of the ideas of thermodynamics in his discussion of the efficiency of an idealized engine. Sadi Carnot's work provided a basis for the formulation of the first law of thermodynamics—a restatement of the law of conservation of energy—which was stated around 1850 by William Thomson, later known as Lord Kelvin, and Rudolf Clausius. Lord Kelvin, who had extended the concept of absolute zero from gases to all substances in 1848, drew upon the engineering theory of Lazare Carnot, Sadi Carnot, and Émile Clapeyron–as well as the experimentation of James Prescott Joule on the interchangeability of mechanical, chemical,
19th-century French art 19th-century French art 19th-century French art was made in France or by French citizens during the following political regimes: Napoleon Bonaparte's Consulate (1799-1804) and Empire (1804-1814), the Restoration under Louis XVIII and Charles X (1814-1830), the July Monarchy under Louis Philippe d'Orléans (1830-1848), the Second Republic (1848-1852), the Second Empire under Napoleon III (1852-1871), and the first decades of the Third Republic (1871-1940). Many of the developments in French arts in this period parallel changes in literature. For more on this, see French literature of the 19th century. For more on French history, see History of France. The French Revolution