was an American inventor who created the impulse water turbine, a key to the commercial development of hydroelectric power. The Pelton wheel introduced an entirely new physical concept to water turbine design (impulse as opposed to reaction). In Pelton’s impulse wheel, water pressure is turned into kinetic energy with a nozzle. The resulting water jet impacts curved turbine blades, reversing the water's flow, causing the runner to spin. This proved to be a more effective design in converting energy in water flow to useful work. The impulse turbine was especially well adapted for high head sites. The first Pelton wheel was used at the Mayflower Mine in Nevada City, California in 1878. In 1887, a miner attached Pelton's wheel to a dynamo and produced the first hydroelectric power in the Sierra Nevada Mountains.