Duchamp has been compared to Leonardo da Vinci, as a profound philosopher-artist. But there is also a comparison to be made with Buster Keaton, another handsome deadpan clown whom Duchamp somewhat resembled. He valued humour, telling a New York newspaper that, "People took modern art very seriously when it first reached America because they believed we took ourselves very seriously. A great deal of modern art is meant to be amusing."
The context for the purchase and naming of Fountain was a worthy exhibition by the Society of Independent Artists, formed on the model of the Parisian Salon des Indépendants. It was to show works by anyone, subject to a fee of $1 for membership and $5 annual dues. Duchamp himself, as a celebrated foreign artist, was on the board, as were various prominent American painters and art world figures. From early on, however, Duchamp seemed tempted to subvert the whole enterprise.
His first move was to suggest that the works in the New York exhibition be hung alphabetically, with the first letter to be drawn out of a hat. This idea was adopted, despite protests that it was "democracy run riot". As a result, the whole huge show - the largest ever assembled in the US - must have had a slightly absurd air, with traditionalist, amateur works sent in from the sticks hung randomly beside pieces of cutting-edge cubism.
But, not content, Duchamp further added to the mayhem with the submission of Fountain, accompanied by the non-existent R Mutt's $6 fee and an invented address in Philadelphia. It was a missile aimed with brilliant precision at the basis of the exhibition - its democratic open admission. Here was an unmentionable object - press reports at the time referred to it as a "bathroom appliance" - it was signed and dated, but was it a work of art? If not, why not?
This deadpan style of question was very much Duchamp's technique. At the Arensbergs' salon - "an inconceivable orgy of sexuality, jazz and alcohol", according to Gabrielle Buffet-Picabia, wife of the artist Picabia who frequented it, as did Man Ray - Duchamp demoralised the writer William Carlos Williams with a similar query. Williams remarked that he liked a certain painting.
"He looked at me and said, 'Do you?'," said Williams. "That was all. He had me beat all right, if that was the objective. I could have sunk through the floor, ground my teeth, turned my back on him and spat."
It must have been the way Duchamp asked this apparently innocuous question - with underlying implications of "Do you really like it?" "Why do you like it?" "Are you sure what it is?"
George Bellows, a leading painter of a gritty, realist persuasion and member of the board of the Society of Independent Artists, was similarly outraged by Fountain. According to Beatrice Wood, a young artist then in love with Duchamp, Bellows complained that it could not be exhibited as it was indecent. He suspected a joke; the name R Mutt struck him, understandably, as "fishy". Walter Arensberg countered by pointing out that the correct fee had been paid. "'You mean to say, if a man sent in horse manure glued to a canvas that we would have to accept it!', said Bellows. 'I'm afraid we would,' said Walter."
In the event, the board narrowly voted not to show Fountain, and, according to one account, it was hidden behind a screen. Duchamp must have been pleased with his work, quite apart from the satisfactory ruckus it caused, because shortly afterwards he arranged to have it photographed by Alfred Stieglitz, taking a good deal of trouble over the result.
This image is the only remaining record of the original object. It was reproduced with an anonymous manifesto the following May in an avant-garde magazine called The Blind Man. The accompanying text made a claim crucial to much later modern art: "Whether Mr Mutt made the fountain with his own hands or not has no importance. He CHOSE it. He took an article of life, placed it so that its useful significance disappeared under the new title and point of view - created a new thought for that object." It was this publication as much as the initial scandal which made Fountain famous.
And what happened to the original? The best guess, according to Calvin Tomkins in his biography of Duchamp, is that it was thrown out as rubbish by Stieglitz shortly afterwards (a common fate of Duchamp's early ready-mades). By a delicious irony that the artist must have enjoyed, all the versions of Fountain now extant - including the one in the Tate show - are not ready-made at all, but carefully crafted hand-made facsimiles of that "Bedfordshire" urinal.