Charles Wheatstone

Charles Wheatstone invented the electric telegraph, the stereoscope, the Playfair cipher, and the English concertina. He was also a friend of the Fourth Doctor's. According to the Doctor, noted scientist as he was, Wheatstone was very bad at golf.

When the Doctor attempted to take Ann Kelso to visit Wheatstone in 1852, they found that he no longer existed. His house in London, 168 Bleak Lane, was also replaced by a different house, which seemed to have always been there. Later, Ada Lovelace confirmed that she had never heard of him. (AUDIO: The Enchantress of Numbers)