© Licensed to London News Pictures. 02/02/2012, London, UK. A gallery assistant uses a spirit level to hang artist Raoul Dufy's 'Atelier de la rue Jeanne-d'arc, nu couch au passant. The painting is expected to raise 250,000-350,000GBP. Photo call at Bonhams, London for Impressionist and Modern Art Auction preview.. Photo credit : Stephen Simpson/LNP