Gustave Eiffel the city of Dijon, Côte-d'Or, the first child of Catherine-Mélanie (née Moneuse) and Alexandre Bönickhausen (). He was a descendant of Jean-René Bönickhausen, who had emigrated from the German town of Marmagen and settled in Paris at the beginning of the 18th century. The family adopted the name Eiffel as a reference to the Eifel mountains in the region from which they had come. Although the family always used the name Eiffel, Gustave's name was registered at birth as Bonickhausen dit Eiffel, and was not officially changed to Eiffel until 1880. At the time of Gustave's birth his father, an
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