BALAUSTRADE. - A railing consisting of equal vertical elements, called balusters or small balusters, often rising from a common base and always connected at the top by a flat element serving as a sill; this flat element may be similar to any lower molding. It is clearly distinct from the transenna (perforated screen), since the latter, instead of being formed, like the balustrade, by independent and repeated elements, is a pierced pluteus. The balustrade, in its most common form, originated from the system of enclosing loggias when, in application of the Gothic principle of eliminating inert masses, solid parapets or plutei were articulated into individual vertical supports. In religious architecture, it has the precise purpose of enclosing or separating certain zones from the rest of the church and thus replaces plutei, parapets, and transennae; it became necessary when, with the abolition of the raised presbytery area typical of the Romanesque period, the pluteus or transenna had also fallen into disuse. It was also regularly used to limit access to chapels when, in the 15th century, the custom developed—and thus the desire arose—to isolate tombs or noble areas from the common space of the naves. The shape of the balusters and the color of the marbles varied considerably over time. In general, the balustrades of sacred buildings follow the development of those in secular constructions. In the 15th century, there are still a few rare examples of transennae, such as those with amphorae between scrolls in the Old Sacristy of S. Lorenzo in Florence; but already in the pulpit of S. Maria Novella, the balustrade has vertical elements differentiated into small columns. In examples by Michelozzo or in the Carafa Chapel in S. Maria sopra Minerva in Rome, the balustrine is elegant as it tapers at the ends, differentiating into two symmetrical halves. There still exist some solid railings improperly called balustrades, such as the Roman one in S. Maria del Popolo from the workshop of A. Bregno.
By the early 16th century, the elegant and slender line of the balusters gave way to greater massiveness that weighed down the curves, while the recesses became more pronounced; finally, of the two similar halves, only the upper one remained, and the lower was replaced by a small base. This evolution occurred rapidly in Rome from Bramante to Sangallo and Vignola; Giacomo della Porta already accentuated the swellings and recesses in the church of S. Maria dei Monti. With Maderno, the balustrade was used as a terminal element of a façade on the two slopes of the pediment (S. Susanna), so that the plastic masses expanded with a more gradual transition into space. Borromini, in the cloister of S. Carlino alle Quattro Fontane, placed a straight baluster next to an inverted one to create a continuous and insistent rhythm even in a part necessarily devoid of movement. Meanwhile, in the course of the 17th century, the coloring of the marbles became more vivid, the curves became increasingly pronounced, and the entire balustrade lost its original rectilinear character. Pietro da Cortona, in the Gavotti Chapel in the church of S. Niccolò da Tolentino, used balusters of complex profiles and square sections; finally, Borromini, in the Spada Chapel in the church of S. Girolamo della Carità, with imaginative adherence to the function of the balustrade during the administration of the Eucharist, removed all architectural elements and replaced them with a marble drapery supported by angels. In the 18th century, the tones of the marbles became subdued, the profiles lost their soft 17th-century character, and the sense of emptiness returned to predominate. 19th-century architects drew variously on past forms according to their eclectic orientation. In modern constructions, however, when the motif of the transenna is not revived, the individual vertical elements are reduced to their essence as supports with square or circular sections, and the architect’s interest focuses predominantly on proportions and spacing.
BIBL.:
G. Matthiae, *Il restauro dei monumenti*, Roma 1939;
G. De Angelis d’Ossat, *Elementi di architettura e di composizione architettonica*, Roma 1945;
G. C. Argan, *L’architettura italiana del Quattrocento*, in *Storia dell’arte italiana*, Firenze 1946.