Until 1977, London had a #Hydraulic Power Company which provided (up to) 5.2 MW of 800psi (5.5MPa) water to power machinery throughout the city; from 1871 to 1923 it was pumped by coal-fired steam engines, and later by electrical pumps. #history
on 02016-07-21a third Wiki page about quantitative analogies between #mechanical (in this case #hydraulic) systems and electrical systems.
on 02016-07-21