Man Ray’s celebrated combination of a metronome with a photograph of an eye affixed with a paperclip to the swinging arm was first created in 1922-3 and titled “Object to be Destroyed” (Objet à détruire). As Man Ray later explained:
'I had a metronome in my place which I set going when I painted - like the pianist sets it going when he starts playing - its ticking noise regulated the frequency and number of my brushstrokes. The faster it went, the faster I painted; and if the metronome stopped then I knew I had painted too long, I was repeating myself, my painting was no good and I would destroy it. A painter needs an audience, so I also clipped a photo of an eye to the metronome’s swinging arm to create the illusion of being watched as I painted. One day I did not accept the metronome’s verdict, the silence was unbearable and since I had called it, with a certain premonition, Object of Destruction, I smashed it to pieces.'
In 1933 Man Ray remade the scupture, this time featuring the eye of Lee Miller — model, photographer, and his lover of three years who had abandoned him the year previous. Man Ray wrote instructions for the creation of the object this time titled “Lost Object":
“Cut out the eye from a photograph of one who has been loved but is seen no more. Attach the eye to the pendulum of a metronome and regulate the weight to suit the tempo desired. Keep doing to the limit of endurance. With a hammer well-aimed, try to destroy the whole at a single blow.”
In 1958 Man Ray remakes the object yet again - under the title “Indestructible Object.”
Reed Enger, "Indestructible Object," in Obelisk Art History, Published March 18, 2015; last modified July 08, 2018, http://arthistoryproject.com/artists/man-ray/indestructible-object/.