Lester Pelton. Portrait of Lester A. Pelton (1829-1909), American inventor. Aged 21, Pelton left Ohio and joined the Californian Gold Rush. He mined unsuccessfully for the next fourteen years. He noted that the steam-driven machinery needed in mines was too expensive and began developing an improved water wheel. He devised the Pelton wheel which has divided buckets along its circumference. These buckets fully reverse the fluid in a water jet, converting the jet's energy with 90% effic- iency. Pelton received a patent for his wheel in the early 1880s. After initially struggling to have the design widely adopted, Pelton was successful and the design is still in use today.