Man Ray's iconic work has had two incarnations and three titles. Richard Cork identifies its singular power

If anything unites the bewildering diversity of Man Ray's work, it is perhaps his overriding fascination with women (see Man Ray Laid Bare). The prodigious range of images by this tireless artist encompasses painting, drawing, photography and film. He also experimented with print-making, but made some of his most personal and unforgettable inventions by assembling witty, often disquieting objects.

It was Marcel Duchamp who propelled Man Ray into realising how potent readymade material could be. The two men met soon after Duchamp scandalised New York with his Nude Descending a Staircase, No. 2, the most fiercely debated exhibit in the great Armory Show of 1913. In 1920 he mocked his own gathering fascination with sex by producing the Priapus Paperweight, a sculpture of male genitals made from steel balls and phallic tubing.

Only when he took the decision to abandon New York did Man Ray's career as an avant-garde artist really flourish. In 1921, soon after Duchamp left for Paris, Man Ray followed. He was immediately introduced to other European Dadaists, who contributed irre v e rent yet welcoming comments to the catalogue of his first French show at the Librarie Six. Its most provocative and unsettling exhibit was only added after the composer Erik Satie had paid a visit. His enthusiastic response prompted Man Ray to make Cadeau, using an ordinary flatiron bought from a nearby shop. By gluing a row of tin-tacks to the iron's up-ended base, he transformed it into an absurdity. Robbed of its former function, the flatiron became redundant and also - more

His love of readymade objects would not go away. In 1923 he acquired a wooden metronome and subverted its meaning by adding to the pendulum a photograph of an eye. Ticking from side to side, it still marks the passage of time. But the eye stares out at the onlooker, who might well become transfixed by its beguiling, shameless gaze. Less than ten inches high, the object's modest size is outweighed by its ability to mesmerise. In a perpetual state of vacillation, the eye ends up frustrating anyone who wants to pin down the work's significance.

The title indicates another layer of meaning. For Man Ray originally called it Object to Be Destroyed. When his lover Lee Miller left him in 1932, he made a notorious ink drawing of the object, inscribed on the back with instructions: 'Cut out the eye from the 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 going to the limit of endurance. With a hammer well aimed, try to destroy the whole with a single blow.' True to the vengeful spirit of this command, Ray proceeded to replace the eye on the metronome with a photograph of Lee's eye. He also gave it a new name: Object of Destruction.

Only in 1957 did anyone obey Ray's order to smash the object. A group of students carried out his instructions at the Exposition Dada in Paris. Although an insurance company official agreed to pay compensation in full, he voiced what Ray described as 'a suspicion that I might, with this money, buy a whole stock of metronomes. That was my intention, I replied; however I assured him of one thing - I'd change the title.'

He fulfilled his promise, too. In 1958, Object of Destruction's name was once again altered, this time to Indestructible Object. The new title should not be taken too literally: it is still a vulnerable work. But perhaps Man Ray wanted the defiant words 'Indestructible Object' to reflect the fact that it could be repeated indefinitely. He ensured that the work was produced in a large edition, prompting his old friend Roland Penrose to observe that Indestructible Object was now 'reproduced in numbers which allow them to attain the status of household gods.' Man Ray may have also intended to imply that, even if the entire edition was obliterated, the work would live on - above all in the memories of those who had encountered the hypnotic, ticking eye and found themselves bewitched.