In the context of the Universal Exposition, many Structure Design Offices around the world were competing to win the construction of a central Masterpiece . The First drawing of the Eiffel Tower is born in June 1884 from the two engineers Maurice Koechlin et Émile Nouguier.
It wasn't a nice design and when Mr. Eiffel saw it he told them that he wasn't interested. The tower was simplistic design ,with a height of 300m
Here is the first drawing (click on it to see a bigger picture)
They brought the drawing to the attention of the chief engineer Mr Sauvestre. He reworked the legs curves, giving them a wider base of 105m and removed 2 floors. The height stayed at 300m. But the design was still not elegant enough and he added the "Pont de l'Arc" which unifies the legs under the first floor giving a feeling of strenght. The Pont de l'Arc is purely cosmetic and has no structural role. The Pont de l"arc became the signature of the Eiffel Tower in its pure Art Deco style.
When Mr. Eiffel saw the drawing he was charmed.