> The Eiffel Tower

Eiffel built hundreds of metal structures of all kinds, all around the world. Bridges, and in particular railway bridges, were his favourite field of work, but he also won renown for his metal structural work and industrial installations. His career was marked by a large number of fine buildings, among which two of the most outstanding are the twin edifices of the Porto viaduct and the Garabit viaduct in the Cantal region of France. Equally outstanding are certain other structures in which the pure inventiveness of Eiffel's company was allowed free rein, such as the "portable" bridges sold around the world in "kits", the ingenious structure of the Statue of Liberty in New York, and of course the Eiffel Tower itself.

All the elements were prepared in Eiffel’s factory located at Levallois-Perret on the outskirts of Paris. Each of the 18,000 pieces used to construct the Tower were specifically designed and calculated, traced out to an accuracy of a tenth of a millimetre and then put together forming new pieces around five metres each. A team of constructors, who had worked on the great metal viaduct projects, were responsible for the 150 to 300 workers on site assembling this gigantic erector set.

The assembly of the first level was achieved by the use of twelve temporary wooden scaffolds, 30 metres high, and four larger scaffolds of 40 metres each. "Sand boxes" and hydraulic jacks - replaced after use by permanent wedges - allowed the metal girders to be positioned to an accuracy of one millimetre.

On December 7, 1887, the joining of the major girders up to the first level was completed.

The pieces were hauled up by steam cranes, which themselves climbed up the Tower as they went along using the runners to be used for the Tower's lifts.

It only took five months to build the foundations and twenty-one to finish assembling the metal pieces of the Tower.