I've got interested, since I am going with about 10 of my students to Paris for the Euromech conference I am coorganizing in July, by the design of the Eiffel Tower.  Eiffel was a great engineer, and indeed his shape of the tower apparently comes from his ingenious idea of  balancing weigth and wind pressure so that there is little need of foundations.  WIKIPEDIA has an account of this design idea, and the resulting integro-differential equation.

 
I added a preprint with permission of the Solution of Eiffel-Chouard equations by Weidman and Pinelis as attachment here, together with actual Excel file of the Eiffel tower profile measurement by Eiffel himself and others.... Have fun!

I am going to Modena on Monday to talk to my collegues in the Millechili lab (MilleChili means 1000Kg in italian)