Marcel Duchamp - The Bride Stripped Bare by Her Bachelors, Even

What we were interested in at the time was the fourth dimension. Simply, I thought of the idea of a projection, of an invisible fourth dimension, something you couldn't see with your eyes.



Philadelphia Museum of Art: Handbook of the Collections
Surely one of the most enigmatic works of art in any museum, The Large Glass dominates a gallery devoted to Marcel Duchamp's work from the exact location in which he placed it in 1954. Painstakingly executed on two planes of glass with unconventional materials such as lead foil, fuse wire, and dust, the appearance of the Glass is the result of an extraordinary combination of chance procedures, carefully plotted perspective studies, and laborious craftsmanship. As for its metaphysical aspect, Duchamp's voluminous preparatory notes, published in 1934, reveal that his "hilarious picture" is intended to diagram the erratic progress of an encounter between the "Bride," in the upper panel, and her nine "Bachelors" gathered timidly below amidst a wealth of mysterious mechanical apparatus. Exhibited only once (in 1926 at the Brooklyn Museum) before it was accidentally broken and laboriously repaired by the artist the Glass joined the Museum's collection in 1953 and has gradually become the subject of a vast scholarly literature and the object of pilgrimages for countless visitors drawn to its witty, intelligent, and vastly liberating redefinition of what a work of art can be. Anne d'Harnoncourt, from Philadelphia Museum of Art: Handbook of the Collections (1995), p. 316.

http://www.philamuseum.org/collections/permanent/54149.html