But it was only when the Cathedral of Santa Maria del Fiore was built that Brunelleschi was able to show his true intelligence. In 1418 the dome of the cathedral had yet to be defined, this was because no one knew how to build a dome large enough to contain the cathedral. The reason it was so difficult to figure out how to build this dome was because buttresses were prohibited and it was not possible to get scaffolding beams long and strong enough to build the dome. So to solve the problem, the Arte della Lana launched a competition. Brunelleschi won the competition because he was the only one who could keep an egg standing on a piece of marble. The way he said he did it was by “… giving one end a blow on that flat piece of marble, making it stand upright… The architects protested that they could have done the same; but Filippo replied laughing that they could have built the dome if they had seen his design. (Martin 78). Brunelleschi continued to build the dome, inventing a machine to lift the dome