If you're a collector of paintings of clowns, then you're probably already aware of Jim Howle. His website describes him as "the best-known clown artist in the world." He's actually the only clown artist that I know of, though I'm sure there must be others.
In 1979, when Henri Gugelmann debuted his "rat circus" in downtown Bern, he claimed it was the first of its kind in the world. And maybe it was also the last, because I don't know where one would go today to see performing rats.
His trained rats jumped over ropes, ran through burning rings, and crawled along in a "rat race" while Gugelmann, dressed as a clown, directed the show. That sounds like quality entertainment! [Google News: Victoria Advocate, Aug 9, 1979]
Denison's make-up guide (1926) was a catalogue of the various products sold by Denison, but it also offered detailed instructions on how to use their products. Below is their guide for "blacking up" using their Superfine Minstrel Black make-up paint. There were similar how-to's for other ethnic types such as the 'Ghetto Jew,' the Japanese, Irishman, Chinaman, etc. See more images from the catalogue at UVA's online exhibit, Uncle Tom's Cabin & American Culture.
This puzzle appeared in The Strand magazine, December 1903, demonstrating that swastikas and clowns had an affinity for one another even before the Nazis came along. (Technically it's a Sauwastika Clown Puzzle, not a Swastika one.) The answer is below in extended.