Model showing section of the lantern of the dome by Franco Gizdulich (2015). This section model provides an easy-to-grasp overview of the complexity of the architectural structure of the lantern designed by Brunelleschi for his dome, both internally and externally. The lantern primarily fulfills a static necessity, its weight “closing” and stabilizing the ribbed sails of the dome. But it also crowns it aesthetically, echoing the pattern of the eight ribs with its graceful buttresses, which create a sort of gallery around the lantern itself. A staircase is concealed within the structure accessing the steeple and the huge ball in gilded bronze with the cross.