The starting point for the sculpture Sablier [hourglass] (2008) by the Welsh conceptual artist Bethan Huws is Marcel Duchamp’s early readymade Fountain, 1917. In that year, the jury of the New York ‘Society of Independent Artists’, of which the artist Marcel Duchamp was also a member, decided not to allow a urinal signed “R. Mutt 1917” that had been submitted as a sculpture to be admitted into its annual exhibition. A historical photo shows the urinal rotated 180 degrees in a horizontal position on a sculpture plinth, instead of its intended vertical position on a wall. Bethan Huws picks up on the play on meanings initiated by these conceptual decisions by creating an hourglass that is not only very large in size, but also signed on both sides. The signature on the bottom left is reflected in an upside-down second signature on the top/bottom, if the hourglass is turned through 180 degrees in accordance with its intended function. As in Duchamp’s case, the signature not only determines and undermines the orientation of top and bottom, but also simultaneously guides and destabilizes the observer’s/user’s perceptions. By repealing the opposition of top and bottom, time flows back into itself in an endless movement.