The Eiffel Tower
The Eiffel Tower is one of the most iconic landmarks in the world, located in Paris, France. Built in 1889 for the Exposition Universelle (World's Fair) to celebrate the 100th anniversary of the French Revolution, it stands at 324 meters tall.
The tower has three levels that are open to the public, offering breathtaking views of Paris. The iron lattice structure and intricate design make it an engineering marvel and a symbol of French culture.
Work on the foundations started on 28 January 1887. Those for the east and south legs were straightforward, with each leg resting on four 2 m (6.6 ft) concrete slabs, one for each of the principal girders of each leg. The west and north legs, being closer to the river Seine, were more complicated: each slab needed two piles installed by using compressed-air caissons 15 m (49 ft) long and 6 m (20 ft) in diameter driven to a depth of 22 m (72 ft) to support the concrete slabs, which were 6 m (20 ft) thick. Each of these slabs supported a block of limestone with an inclined top to bear a supporting shoe for the ironwork.
The main structural work was completed at the end of March 1889 and, on 31 March, Eiffel celebrated by leading a group of government officials, accompanied by representatives of the press, to the top of the tower. Because the lifts were not yet in operation, the ascent was made by foot, and took over an hour, with Eiffel stopping frequently to explain various features. Most of the party chose to stop at the lower levels, but a few, including the structural engineer, Émile Nouguier, the head of construction, Jean Compagnon, the President of the City Council, and reporters from Le Figaro and Le Monde Illustré, completed the ascent. At 2:35 pm, Eiffel hoisted a large Tricolour to the accompaniment of a 25-gun salute fired at the first level.
The puddle iron (wrought iron) of the Eiffel Tower weighs 7,300 tonnes, and the addition of lifts, shops and antennae have brought the total weight to approximately 10,100 tonnes. As a demonstration of the economy of design, if the 7,300 tonnes of metal in the structure were melted down, it would fill the square base, 125 metres (410 ft) on each side, to a depth of only 6.25 cm (2.46 in) assuming the density of the metal to be 7.8 tonnes per cubic metre. Additionally, a cubic box surrounding the tower (324 m × 125 m × 125 m) would contain 6,200 tonnes of air, weighing almost as much as the iron itself. Depending on the ambient temperature, the top of the tower may shift away from the sun by up to 18 cm (7 in) due to thermal expansion of the metal on the side facing the sun.
Key Facts
| Height | 324 meters |
|---|---|
| Construction | 1887–1889 |
| Architect | Gustave Eiffel |
Visitor Information
Explore more about the Eiffel Tower: