Readymades of Marcel Duchamp to turn up any identical matches to photographs of the originals. However, there are accounts of Walter Arensberg and Joseph Stella being with Duchamp when he purchased the original "Fountain" at J. L. Mott Iron Works. Such investigations are hampered by the fact that few of the original "readymades" survive, having been lost or destroyed. Those that still exist are predominantly reproductions authorized or designed by Duchamp in the final two decades of his life. Shearer also asserts that the artwork "L.H.O.O.Q." which is recorded to be a poster-copy of the "Mona Lisa" with a moustache drawn on it, is
Marcel Duchamp be considered "true". "The things themselves are not what science can reach..., but only the relations between things. Outside of these relations there is no knowable reality", Poincaré wrote in 1902. Reflecting the influence of Poincaré's writings, Duchamp tolerated any interpretation of his art by regarding it as the creation of the person who formulated it, not as truth. Duchamp's own art-science experiments began during his tenure at the library. To make one of his favorite pieces, "3 Standard Stoppages" ("3 stoppages étalon"), he dropped three 1-meter lengths of thread onto prepared canvases, one at a time, from a height