Art has played upon this subjectivity for centuries, from Holbein's depiction of a skull in his painting The Ambassadors, to the Surrealism of Salvador Dali, M.C. Escher and Marcel Duchamp, and the Optical Art movement of the late 1950s. As Mel Gooding stresses in the introduction to this unusual collection, the eye is merely the tool of the mind and between the master and its lackey lies an expanse of perception in which conventional meaning can be deconstructed to be reconstructed as art, challenging the very precepts of our consciousness. This is something at once exhilarating and exhausting. Julian Rothenstein and Mel Gooding have principally plundered the collections of two men, James Dalgety and Edward Hordern, to assemble a phantasmagoria of visual puns and trickery, mainly from the 19th and early 20th centuries. The ephemera that bore such artistic sorcery included match boxes, postcards, cigarette cards and playing cards, attesting to the popularity of the visual gag, and providing the perfect manipulatable medium for it. Thus there are The Upside Downs (illustrating E.H. Goodrich's ideas of "physiognomic perception"), visual palindromes, hidden silhouettes, the Oriental tradition of one head with many bodies, "Rebus" (when words within a context are replaced by symbols, familiar from the television game show Catchphrase), even a palindromic piece of music, as well as encodements adopted for satirical or political comment. Whether infuriating, delightful or both, depends on your patience, but the editors commendably resist undue explanatory interference, allowing the pictures to speak with their forked tongues or remain naggingly silent. An intriguing curio, which leaves you uncertain of whether or not there is a larger meaning behind it all. --David Vincent