Before leaving Paris for New York in 1921, Man Ray made several constructions that questioned the authority of logic and science over the imagination. This quirky instrument, which he called "Compass," was one. The fields of force to which it might respond are as erratic and potentially as destructive as a game of Russian roulette. After making the exposure, Man Ray characteristically disassembled the magnet-and-pistol device, leaving only this single original print as the reminder of a provocative Dada idea. It is "purely cerebral yet material" (as Man Ray said of Marcel Duchamp's "Large Glass"), whimsical yet deadly earnest.
(http://metmuseum.org/art/collection/search/265465?rss=1&utm_source=artwork-of-the-day&utm_medium=rss&utm_campaign=rssfeeds)