Eiffel Tower replicas and derivatives and one in the Isle of Man and sold shares to potential investors, including many prominent Blackpool families. When the corporation got into financial difficultly John Bickerstaffe stopped the scheme from collapsing and ensured the scheme was a success. The Blackpool Tower, though one of the oldest, is not a true replica of the Eiffel Tower and differs from the Paris tower in a number of ways: it is approximately half the height of the Eiffel Tower (158 m compared to 324 m), it is not freestanding and the base contains buildings which house entertainments including the Tower Circus and
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