Engraving made in the late 19th century of two men operating a machine with instrument maker Jesse Ramsden's (1735-1800) modification of a vertical glass disc rather than a cylinder. This machine's basic components were: a drive mechanism, a rotating part which rubbed against cushions causing friction which produced static electricity, and a vessel to collect the charge produced. Some early uses of electricity were medical; it was used to treat paralysis and muscle spasms, and to control heart rates. Illustration from 'Electricity and Magnetism' by Amedee Guillemin (1826-1893), published in London in 1891.
© Science Museum / Science & Society Picture Library