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 forays of witticism and clownery ... the disintegration of the concept of art". Duchamp's notes from the trip avoid logic and sense, and have a surrealistic, mythical connotation. Duchamp painted few canvases after 1912, and in those he did, he attempted to remove "painterly" effects, and to use a technical drawing approach instead. His broad interests led him to an exhibition of aviation technology during this period, after which Duchamp said to his friend Constantin Brâncuși, "Painting is washed up. Who will ever do anything better than that propeller? Tell me, can you do that?". Brâncuși later sculpted bird forms.