Turbine waterwheels. Gas, steam, and water turbines have a casing around the blades that contains and controls the working fluid. Credit for invention of the steam turbine is given both to Anglo-Irish engineer Sir Charles Parsons (1854–1931) for invention of the reaction turbine, and to Swedish engineer Gustaf de Laval (1845–1913) for invention of the impulse turbine. Modern steam turbines frequently employ both reaction and impulse in the same unit, typically varying the degree of reaction and impulse from the blade root to its periphery. The word "turbine" was coined in 1822 by the French mining engineer Claude Burdin from the
George Rennie (engineer) Croydon Railway. Many orders for foreign governments were executed, and the firm were employed by the Admiralty in making engines for the Royal Navy. He was much interested in the screw-propeller, and his firm built the engines for , the world's first propeller-driven steamship. Subsequently, in 1840, the firm built for the Admiralty the "Dwarf", the first vessel in the British navy propelled by a screw. Roe (1916) discusses Rennie's contributions to the development of the planer. In 1822 he was elected Fellow of the Royal Society, and contributed papers to the Transactions in 1829 on the friction of metals