Sir John Ambrose Fleming FRS (29 November 1849 – 18 April 1945), an English electrical engineer and physicist, invented the first thermionic valve or vacuum tube, and also established the left-hand rule for electric motors. He was the eldest of seven children of James Fleming DD (died 1879), a Congregational minister, and his wife Mary Ann, at Lancaster, Lancashire, and baptised on 11 February 1850. A devout Christian, he once preached at St Martin-in-the-Fields in London on evidence for the resurrection. In 1932, he and Douglas Dewar and Bernard Acworth helped establish the Evolution Protest Movement. Childless himself, he bequeathed much of his estate to Christian charities, especially those for the poor. He was a noted photographer, painted water colours, and enjoyed climbing the Alps.
Also known as
Physician, Inventor
