Question

What was the profession of the person who invented the mechanism of the door lock for London toilets operated by payment of a coin, initially one penny?

Answer 1

Stage magician
The pay mechanism was invented by John Nevil Maskelyne (1839 – 1917), a stage magician and illusionist. He also published a book "Sharps and Flats: A Complete Revelation of the Secrets of Cheating at Games of Chance and Skill" on card sharp practices, and in 1914 founded the Occult Committee, a group to "investigate claims to supernatural power and to expose fraud". Pay toilets for men were established in London in the 1850s. Urinals were free. Public toilets for women were not established until some years later.