Sir Ambrose Fleming (1849-1945) was a Lancashireman who invented the vacuum-tube diode or ‘valve’, for fifty years the essential component of modern electronics.
FANNY Umphelby’s ‘Child’s Guide To Knowledge’* can have had few readers more devoted, or more distinguished in later life, than Ambrose Fleming.
Her collection of scientific facts sparked his long career at University College, London, and at the Marconi Company, assisting in the first transatlantic radio transmissions.
Those early transmissions relied on instruments such as Marconi’s magnetic detector, or the gloriously-named ‘cat’s whisker’, to detect them.
On November 16, 1904, Fleming patented his ‘thermionic vacuum tube diode’, which harnessed the Edison Effect (the flow of electrons in a vacuum from a hot cathode filament onto an anode plate) to detect and rectify radio waves.
It was far superior to existing devices, robust enough even for the Navy. For the next fifty years, descendants of Fleming valves were at the heart of electronics, from radios and TVs to radar and computers, until superseded by transistors and a new generation of solid-state devices.
Fanny would have been proud.
* You can read Mrs Umphelby’s scientific catechism online here. Fleming had it by heart, and would quote from it all his life.