 The solid wall, as used at the Pantheon, is lightened at St. Peter's by Bramante piercing it with windows and encircling it with a peristyle.In the case of Florence Cathedral, the desired visual appearance of the pointed dome existed for many years before Brunelleschi made its construction feasible.Its double-shell construction of bricks locked together in herringbone pattern (re-introduced from Byzantine architecture), and the gentle upward slope of its eight stone ribs made it possible for the construction to take place without the massive wooden formwork necessary to construct hemispherical arches.