Fleming's thermionic valve

This valve may look like a Martian tripod but it is in fact one of the fourteen valves used by J. Ambrose Fleming in his early experiments in 1889-90.

Fleming was UCL’s first professor of Electrical Engineering, holding the post from 1885-1926. During this time he also worked closely with Guglielmo Marconi as a scientific consultant researching long-distance radio transmission.