Filippo Brunelleschi had designed the massive octagonal…

Filippo Brunelleschi had designed the massive octagonal dome of Florence’s Gothic cathedral of Santa Maria del Fiore in about 1420.

The Florentine architect intends the vast dome, left unfinished in the fourteenth century because of seemingly insoluble structural problems, to be a self-supporting double shell using new and lighter masonry, and devises new scaffolding and hoists to accomplish this.

The first Italian patent is awarded by the Republic of Florence in 1421, when Brunelleschi receives a three-year patent for a barge with hoisting gear, that carries marble along the Arno River.

He astonishes his contemporaries by completing the soaring structure—one hundred and thirty feet (thirty-nine meters) in diameter and three hundred feet (ninety-one meters) high, with a fifty-two-foot (sixteen-meter) lantern crowning it—without centering (supporting scaffolding).

Brunelleschi begins work in 1421 on the church of San Lorenzo, created, like his Ospedale degli Innocenti, in a new style, employing the details of classical architecture—columns, arches, and pilasters—with a fresh approach, each element being distinctly and visibly in proportion with all other elements.

Brunelleschi designs the church as a three-aisled, Latin cross plan with transept; the unifying elements in it are the square module on which all of the church is designed and the consistent application of the classical orders.