William Armstrong, 1st Baron Armstrong

William Armstrong, 1st Baron Armstrong, was a British engineer and industrialist best known for early hydraulic engineering and for one of the first private applications of hydroelectric power. In 1878 he installed a water turbine at his Cragside estate in Northumberland, using it to generate electricity that lit the house, a system commonly cited as one of the first hydroelectric power installations used to light a private home. Armstrong had already built his reputation on hydraulic power more broadly, developing the hydraulic accumulator that made high pressure hydraulic machinery practical for cranes, dock gates and other heavy industrial equipment, and founding the engineering firm that became Armstrong Whitworth.