abstract:Multiplying billiard balls (Excelsior Ball Trick, August Roterberg, 1898) is a magic routine that is popular with both amateur and advanced conjurors but still rarely seen. As its name implies, the magician uses sleight of hand to manipulate a number of billiard balls (the balls are often smaller than actual billiard balls), giving the impression that he is making them appear and vanish at his command.