Eiffel Tower Parisian window always includes the tower. In reality, since zoning restrictions limit the height of most buildings in Paris to seven storeys, only a small number of tall buildings have a clear view of the tower. Maintenance of the tower includes applying 60 tons of paint every seven years to prevent it from rusting. The tower has been completely repainted at least 19 times since it was built. Lead paint was still being used as recently as 2001 when the practice was stopped out of concern for the environment. The nearest Paris Métro station is Bir-Hakeim and the nearest RER
Eiffel Tower gaps in the latticework. In the years since it was completed, engineers have put forward various mathematical hypotheses in an attempt to explain the success of the design. The most recent, devised in 2004 after letters sent by Eiffel to the French Society of Civil Engineers in 1885 were translated into English, is described as a non-linear integral equation based on counteracting the wind pressure on any point of the tower with the tension between the construction elements at that point. The Eiffel Tower sways by up to 9 centimetres (3.5 in) in the wind. When originally built, the first