David Carlyon was a Ringling Brothers, Barnum & Bailey Circus Clown. He toured with the show and has written a book about that and much more!
The Education of a Circus Clown: Mentors, Audiences, Mistakes
You can purchase the book here.
Vaudevisuals interview with David Carlyon – “The Education of a Circus Clown: Mentors, Audiences, Mistakes”