The design of the Eiffel Tower was originated by Maurice Koechlin and Emile Nouguier, who had discussed ideas for a centrepiece for the 1889 Exposition Universelle. In May 1884 Koechlin, working at his home, made an outline drawing of their scheme, described by him as "a great pylon, consisting of four lattice girders standing apart at the base and coming together at the top, joined together by metal trusses at regular intervals". Initially Eiffel showed little enthusiasm, although he did sanction further study of the project, and the two engineers then asked Stephen Sauvestre to add architectural embellishments. Sauvestre added the decorative arches to the base, a glass pavilion to the first level and the cupola at the top. The enhanced idea gained Eiffel's support for the project, and he bought the rights to the patent on the design which Koechlin, Nougier and Sauvestre had taken out. The design was exhibited at the Exhibition of Decorative Arts in the autumn of 1884, and on 30 March 1885 Eiffel read a paper on the project to the Société des Ingénieurs Civils. After discussing the technical problems and emphasising the practical uses of the tower, he finished his talk by saying that the tower would symbolise