Blackstone, Harry (Henry Boughton). Fredrik the Great and Blackstone Broadsides. American, 1919. Two pictorial broadsides advertising the stage magic shows of Fredrik the Great and Blackstone ? one and the same person. Double-sided plexiglass frames. Images 19 x 6 ??. Minor chips and old cellotape stains. The text, images, and design of each of these broadsides are identical, save one element: the performer?s name. The earlier piece uses the name ?Fredrik the Great,? and the later ?Blackstone.? Harry Blackstone (1885-1965) used the Fredrik the Great stage name for a time, until anti-German sentiment during WWI made him think better of it. He changed his name to Blackstone and rose to fame as American?s most popular illusionist.