James Clark Maxwell

James Clark Maxwell was a scientist who had investigated electromagnetism in 1854. He was mentioned by Theodore Maxtible in a conversation with the Second Doctor in 1866. (TV: The Evil of the Daleks)

In 1867, the Fifth Doctor "borrowed" an electromagnetic field generator from James Maxwell, his friend. (AUDIO: The Haunting of Thomas Brewster)

Behind the scenes
Maxwell famously developed Maxwell's equations.