The design of the Eiffel Tower was originated by Maurice Koechlin and Émile Nouguier, two senior engineers who worked for the Compagnie des Establissments 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 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".[12] 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, and 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 read a paper on the project to the Société des Ingiénieurs 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[13]
"not only the art of the modern engineer, but also the century of Industry and Science in which we are living, and for which the way was prepared by the great scientific movement of the eighteenth century and by the Revolution of 1789, to which this monument will be built as an expression of France's gratitude."
Little happened until the beginning of 1886, when Jules Grévy was re-elected as President and Édouard Lockroy was appointed as Minister for Trade. A budget for the Exposition was passed and on 1 May Lockroy announced an alteration to the terms of the open competition which was being held for a centerpiece for the exposition, which effectively made the choice of Eiffel's design a foregone conclusion: all entries had to include a study for a 300 m (980 ft) four-sided metal tower on the Champ de Mars.[14] On 12 May a commission was set up to examine Eiffel's scheme and its rivals and on 12 June it presented its decision, which was that all the proposals except Eiffel's were either impractical or insufficiently worked out. After some debate about the exact site for the tower, a contract was finally signed on 8 January 1887. This was signed by Eiffel acting in his own capacity rather than as the representative of his company, and granted him one and a half million francs toward the construction costs: less than a quarter of the estimated cost of six and a half million francs. Eiffel was to receive all income from the commercial exploitation of the tower during the exhibition and for the following twenty years. Eiffel later established a separate company to manage the tower, putting up half the necessary capital himself.[15]
