He had just completed twelve Rotoreliefs, optical discs which when placed on the turntable of a phonograph produced the illusion of motion in perspective. He rented a tiny stand among the inventions at the Concours Lépine, [the Paris inventors' fair] near the Porte de Versailles, and waited for the crowds to arrive. I had to go and see that. All the discs were turning around him at the same time, some horizontally, others vertically, a regular carnival...but I must say that his little stand went strikingly unnoticed.
None of the visitors, hot on the trail of the useful, could be diverted long enough to stop there. A glance was sufficient to see that between the garbage compressing machine and the incinerators on the left, and the instant vegetable chopper on the right, this gadget of his simply wasn't useful.
When I went up to him, Duchamp smiled and said, 'Error, one hundred per cent. At least, it's clear.'
From Souvenirs of Marcel Duchamp by H. P. Roché, in Lebel, p. 84-85.
"Thus once again the year 1920 was a time for great decisions since from the position of anti-artist he had to pass to that of engineer. This mutation was to be so important that it required a change of identity. After having thought first of adopting a Jewish name he took the pseudonym 'Rose Sélavy' with which thenceforth he signed his works."
From Marcel Duchamp by Robert Lebel, p. 46
Photo Credit: Marcel Duchamp, Rotorelief 1949, from Lebel, fig 40.