BRUNELLESCHI, Filippo

(c. 1377-1446)

   Filippo Brunelleschi, traditionally considered the founder of early Renaissance architecture in Italy, trained as a goldsmith in Florence and gained an understanding of architecture while studying classical buildings in Rome. Many Renaissance architects were interested in antiquity, but Brunelleschi's desire to examine the proportions and engineering of Roman buildings with mathematical precision enabled him to more fully understand Roman structural innovations. In order to facilitate his more accurate system of measurement, Brunelleschi invented an optical device whereby he created a pinhole at the center of a painted image of the Baptistry of Florence and then angled a mirror toward the front of the image. By looking through the pinhole from the back of the painting, one could see the mirror reflection of the painting, and when the mirror was removed, the actual baptistery, identical in scale, would appear to the viewer. After this experiment was described by Brunelleschi's biographer and friend Antonio Manetti, in his Vita di Filippo Brunelleschi (c. 1480), one-point perspective came to be used by many early Renaissance sculptors and painters, including Donatello and Masaccio.

   Around 1407, Brunelleschi returned to Florence from Rome and received the very prestigious commission to complete the dome of the Florence Cathedral, a church dedicated to Santa Maria del Fiore. This project had languished for more than 40 years because earlier architects did not know how to cover the massive crossing of the existing church with such a large dome. No dome this size had been built since antiquity, and because the knowledge of concrete, seen in the Pantheon dome, remained lost in the Renaissance, Brunelleschi designed a dome that featured the use of bricks to create an interior shell, while wood was used to build an outer shell. Brunelleschi's plan involved the construction of a tall drum covered by a double-shell dome featuring Gothic ribs and a Roman oculus window topped by a classical lantern. Since the 138-foot (42 meter) diameter was too large for any type of a centering device and too tall for any ground scaffolding, each layer of the dome was self-supporting and reinforced between the two shells with interior arches and Roman herringbone-patterned brickwork. The lantern was completed by Brunelleschi's student Michelozzo di Bartolommeo in 1461, and the Cathedral of Florence came to be called the "Duomo" because of its imposing silhouette. Brunelleschi's almost immediate fame rested on the ingenious solutions he proposed to the logistical challenges of such a monumental construction, and he parlayed that fame into a secondary career in theatrical machinery.

   Brunelleschi's subsequent buildings provide a more fully addressed aesthetic system that blends mathematical ratios with classical philosophy and Christian symbolism. In 1419, he was hired to complete the Ospedale degli Innocenti, or Foundling Hospital, in Florence, one of the first public orphanages built since antiquity.

   Civic buildings traditionally had a loggia, or open portico, across the front, and here Brunelleschi's loggia creates a classically harmonious design of nine round arches set in bay units of 10 braccia, or about 20 feet each unit. Because the diameter of each arch is equal to the depth of the porch and the height of each column, the effect is a perfect cube. A green-gray stone, called pietra serena, separates the Composite Corinthian columns and classical arches from the white wall background, while blue terracotta medallions featuring standing swaddled infants appear above each column. A clear relationship between all parts can be found in this building, which is a trait that became the hallmark of Renaissance design.

   Brunelleschi's churches of San Lorenzo and Santo Spirito, both of which were conceived in the 1420s and completed after his death, also demonstrate a classical aesthetic as well as an interest in geometry, but his architectural philosophy is most fully realized in his small Pazzi Chapel, a freestanding building located next to the Gothic church of Santa Croce in Florence that was mainly built in the 1430s. The exterior of the chapel was constructed with an arched, tripartite portico that might have been completed after Brunelleschi's death. The design recalls the Arch of Constantine (built in AD 312-315 to commemorate Constantine's victory over Maxentius) and was subsequently used as a general façade design in the Renaissance to symbolize the triumph of Christianity. The portico ceiling of the Pazzi Chapel, decorated with classicizing shells and coffers, directs the visitor into a spare room articulated with wall molding and marble floor patterning that divides the rectangular room into ratios of 1:2, 1:3, and 1:4 from the crossing square, with an altar square across from the entrance. These divisions continue with explicit number symbolism and religious meaning. For example, the four corner pendentives feature medallions of the four Evangelists, and the 12 wall pilasters divide the room into vertical sections featuring medallions of the 12 apostles located just beneath the entablature. This symbolism is further reinforced in the 12 ribs of the small umbrella dome above the crossing square.

   In these ways, the Pazzi Chapel most fully and clearly realized the Renaissance reverence for the circle, the triangle, and the square, as well as the meaning of these shapes and their numerical equivalents in both classical philosophy and Christian symbolism. Thus, while the dome of the Florence Cathedral displays Brunelleschi's understanding of Roman structural innovations, the Pazzi Chapel, in its simple harmony, best represents Brunelleschi's classical aesthetic.