Conjuring Credits

The Origins of Wonder

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Bulldog Switch Clip

This gimmick was invented by Bob Ostin and marketed by Davenports as “Bob Ostin's Dice Prediction,” 1953. An ad appeared in Pentagram, Vol. 8 No. 2, Nov. 1953, p. 16. Tony Corinda also mentions Ostin's clip in Thirteen Steps to Mentalism, 1958, p. 186. Ostin's clip was made with a rubber band or elastic. The model with a metal spring was developed and marketed in 1959 by Robert Nelson (sharing credit with Syd Bergson) under the name “Nelson's Mental-Gimic; see The Linking Ring, Vol. 38 No. 12, Feb. 1959, p. 11.