 The drag crisis was observed in 1905 by Nikolay Zhukovsky, who guessed that this paradox can be explained by the detachment of streamlines at different points of the sphere at different velocities.Later the paradox was independently discovered in experiments by Gustave Eiffel and Charles Maurain.Upon Eiffel's retirement, he built the first wind tunnel in a lab located at the basis of the Eiffel Tower, to investigate wind loads on structures and early aircraft.