The design of the Eiffel Tower was originated by Maurice Koechlin and Émile Nouguier, two senior engineers who worked for the Compagnie des Établissements Eiffel, after discussion about a suitable centrepiece for the proposed 1889 Exposition Universelle, a World's Fair which would celebrate the centennial of the French Revolution. In May 1884 Koechlin, working at 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".[3] Initially Eiffel himself showed little enthusiasm, but he did sanction further study of the project, and the two engineers then asked Stephen Sauvestre, the head of company's architectural department, to contribute to the design. Sauvestre added decorative arches to the base, a glass pavilion to the first level, and other embellishments. This enhanced version gained Eiffel's support: he bought the rights to the patent on the design which Koechlin, Nougier, and Sauvestre had taken out, and the design was exhibited at the Exhibition of Decorative Arts in the autumn of 1884 under the company name. On 30 March 1885 Eiffel presented a paper on the project to the Société des IngiénieursCivils; after discussing the technical problems and emphasising the practical uses of the tower, he finished his talk by saying that the tower would symbolise[4]