For the Universal Exhibition of 1889, a date that marked the centenary of the French Revolution, the Journal Officiel launched a major competition to “study the possibility of erecting an iron tower on the Champ-de-Mars. The tower would have a square base, 125 metres on each side and 300 meters high”. The project proposal by entrepreneur Gustave Eiffel, engineers Maurice Koechlin and Emile Nouguier and architect Stephen Sauvestre was chosen out of a total of 107. The construction of the Eiffel Tower in 1889 was Eiffel's crowning achievement. His career as an entrepreneur would come to an end with the failure of the Panama Canal project. From then on, he devoted his time to operating the Tower and to various experiments in air resistance, the observation of meteorology and especially the installation of a giant antenna for the earliest radio broadcasts. Indeed, it is because of these experiments that the Eiffel Tower is still standing, since it was initially built to last 20 years.