a casing can be placed around the turbine to control the movement of the fluid. credit for the invention of the steam turbine is given both to anglo-irish engineer sir charles parsons (1854 - 1931) for invention of the reaction turbine(turbines that utilize water pressure and water speed to rotate), and to the swedish engineer gustaf de laval (1845-1913) for invention of the impulse turbine. modern steam turbines normally utilize both the reaction and impulse turbine in one system.