Sauvestre, Stephen Koechlin, Maurice Nouguier, Emile Architects/Eiffel Tower Architectural Foundation.
The Eiffel Tower is a monument to technology and human ingenuity located in the Champ de Mars section of Paris, France. It was designed by engineer Gustave Eiffel and built by SNCF (French Railways). Opened in 1889 as the world's first permanent steel structure, it has been called "the eighth wonder of the world". Today, it is a popular tourist destination and symbol of Paris.
The tower is 164 m (535 ft) high and consists of a thin tubular steel frame with horizontal bands of iron and glass. The upper part is covered with sheets of stainless steel, which are also used for the antennae. The entire structure is illuminated at night by thousands of lights.
As well as being an icon of Paris, the Eiffel Tower has become a worldwide symbol for engineering and innovation. It is estimated that some 20 million people a year visit its observation decks, making it the most photographed monument in the world.
The Eiffel Tower
|The Eiffel Tower|
|Design and construction|
Gustave Eiffel (1832-1923) designed the Eiffel Tower, which bears his name. But he wasn't the only one working to make his idea a reality. Maurice Koechlin and Emile Nouguier, two engineers from his business, were also recognized for their contributions to the project. The facility employed between 120 and 200 individuals. It was completed in 1889.
The Eiffel Tower is made up of iron girders that support a wooden platform at each floor. The base is about 70 feet high and consists of 830 square feet of wood decking. The elevator used to ascend the tower remains in operation today. It can carry 50 people at a time and takes about 10 minutes to travel from the ground floor to the top.
When it was first built, the Eiffel Tower was the tallest structure in Paris. Today, it is ranked number three, behind the Chrysler Building and the Louvre Pyramid. The tower's height is approximately 420 feet, including the antennae. Its diameter at the base is 78 feet, and its mass is 22 tons. The total cost of the project was $7 million ($90 million in 2005 dollars).
Electricity was first transmitted along a wire strung between two poles in 1882 by Italian physicist Antonio Meucci. In 1913, the American inventor Harvey Hubbell created the now-common push button cell phone.
In acknowledgment of their efforts, the names of 72 French scientists, engineers, and mathematicians are etched on the Eiffel Tower. The carvings may be seen on the sides of the tower under the first balcony, in 60 cm (24 in) tall letters that were originally painted in gold.
There is also writing on some of the scientists who are represented here. For example, you can read the words "Louis Pasteur" and "Georges Lemaitre" on the side of the tower facing the Jardin des Plantes.
The writers' names and dates of birth and death are shown in black and white marble plates attached to the base of the monument. Some of the people depicted here have been friends or rivals of Gustave Eiffel, the man who designed the tower. Others include scientists who contributed ideas for inventions used in building techniques today. Among them are René Laennec, who invented the stethoscope; André-Louis Danjon, who improved upon this device; and Jacques Louis de Francqui, a naturalist who was one of the first people to describe bacteria.
The writers on the Eiffel Tower include many scientists who have been called "the father of..." something. For example, Louis Pasteur is known as the father of vaccination because he developed methods for preventing illness caused by viruses.
Georges Lemaître invented the hydrogen bomb.
Eiffel, who was adept in building open lattice structures, designed the tower to resist wind forces of 4 kN/m2. It can therefore withstand winds of up to 120 km/hr (75 miles/hr). Should a wind exceed this strength, the main structure would have to be reinforced or the tower would collapse.
The Eiffel Tower is made of iron and steel. And its designer, Gustave Eiffel, also invented the crane so it's not surprising that the tower is very strong. It can support itself without any support from beneath ground level. The only parts of the structure that touch the ground are the feet. The rest is about 100 m (330 ft) above sea level.
It was built for the World's Fair in Paris but has since become a popular tourist attraction. It was opened to the public in 1889.
The base of the tower is 5 m (16 ft) thick and weighs about 18 million kg (40 million lb). The overall size of the tower is 130 m (430 ft) tall with an inner diameter at the top of about 10 m (33 ft). It weighs about 2300 t (610,000 lbs).