Piculiarities of Brunelleski's project

Model Brunelleski had other characteristic properties. For instance, drain pipes were arranged outside the building and openings in the external arch scattered wind loads and increased stability to the earthquakes. Brunelleski used cast iron consoles as the support for the scaffolding, on which the artists could work, writing frescoes and laying out mosaic. Brunelleski equipped a kitchen on the upper tiers of scaffolding so that it was not necessary for workers to get down for the food.

The outer shell of arch protected inner shell from severe rains and winds. In the apex of cupola, where eight edges of external and inner shells converge, Brunelleski’s project provided for round rock enclosure, called seralo. Each of eight faces of opening had three windows, which passed light and air into seralo.

Critical element was the lamp, so the competition for construction of which was declared. Brunelleski’s project was a success. One of eight columns of lamp was hollow and there was the steep stairs, which ensured an access to the tent, to which the sphere and cross are fastened. The weight of lamp is transferred to eight edges of cupola, which increases the stability of entire construction. Cathedrals in Italy are frequently crowned by sphere and cross - by symbols of the dominion of Cardinal and Saint Peter in Rome.