Josef Kohn of Vienna became Michael Thonet's largest competitor in making Bentwood furniture. While Thonet required one to two hours to make their wooden rods flexible using steam, their rival Kohn had installed a machine which could produce these parts within 3 - 5 minutes. For the Parisiene World Trades Fair of 1900 the Kohn brothers appointed the Viennese architect Josef Hoffmann and his pupil Gustav Siegel as members of their design team. Siegels Exhibition Room won the Grand Prix of the Fair for the Kohn brothers. In light of this success the Thonet company expanded their work with architects and designers. Joining teams, they created the famous 'Schaukelsessel No 9' Chair which is featured in the Vitra Miniatures Design Museum.