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The design of the Eiffel Tower was the product of Maurice Koechlin and Émile Nouguier, two senior engineers working for the Compagnie des Établissements Eiffel, after discussion about a suitable centrepiece for the proposed 1889 Exposition Universelle, a world's fair to celebrate the centennial of the French Revolution. Eiffel openly acknowledged that inspiration for a tower came from the Latting Observatory built in New York City in 1853. In May 1884, working at home, Koechlin made a sketch of their idea, 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.
The proposed tower had been a subject of controversy, drawing criticism from those who did not believe it was feasible and those who objected on artistic grounds. These objections were an expression of a long-standing debate in France about the relationship between architecture and engineering. It came to a head as work began at the Champ de Mars: a
Committee of Three Hundred (one member for each metre of the tower's height) was formed, led by the prominent architect Charles Garnier and including some of the most important figures of the arts, such as Adolphe Bouguereau, Guy de Maupassant, Charles Gounod and Jules Massenet. A petition called "Artists against the Eiffel Tower was sent to the Minister of Works and Commissioner for the Exposition, Charles Alphand, and it was published by Le Temps on 14 February 1887. Gustave Eiffel responded to these criticisms by comparing his tower to the Egyptian pyramids: "My tower will be the tallest edifice ever erected by man. Will it not also be grandiose in its way? And why would something admirable in Egypt become hideous and ridiculous in Paris? These criticisms were also dealt with by Édouard Lockroy in a letter of support written to Alphand, ironically saying, Judging by the stately swell of the rhythms, the beauty of the metaphors, the elegance of its delicate and precise style, one can tell this protest is the result of collaboration of the most famous writers and poets of our time, and he explained that the protest was irrelevant since the project had been decided upon months before, and construction on the tower was already under way. At first the legs were constructed as cantilevers, but about halfway to the first level, construction was paused in order to create a substantial timber scaffold. This renewed concerns about the structural integrity of the tower, and sensational headlines such as "Eiffel Suicide" and "Gustave Eiffel Has Gone Mad: He Has Been Confined in an Asylum" appeared in the tabloid press. At this stage, a small "creeper" crane designed to move up the tower was installed in each leg. They made use of the guides for the lifts which were to be fitted in the four legs. The critical stage of joining the legs at the first level was completed by the end of March 1888. Although the metalwork had been prepared with the utmost attention to detail, provision had been made to carry out small adjustments in order to precisely align the legs; hydraulic jacks were fitted to the shoes at the base of each leg, capable of exerting a force of 800 tonnes, and the legs were intentionally constructed at a slightly steeper angle than necessary, being supported by sandboxes on the scaffold. Although construction involved 300 on-site employees, only one person died thanks to Eiffel's stringent safety precautions and the use of movable gangways, guardrails and screens.
The start of the erection of the metalwork.
7 December 1887: Construction of the legs with scaffolding.
20 March 1888: Completion of the first level.
15 May 1888: Start of construction on the second stage.
21 August 1888: Completion of the second level.
26 December 1888: Construction of the upper stage.
15 March 1889: Construction of the cupola.
