This screen, which is still standing, is probably not older than the
sixteenth century. It is composed of an elevated basement of marble,
about five feet high, and divided above this into compartments, by
square pillars of marble, supporting an entablature, and the spaces
between them being filled by a bronze grating of crossing bars, making a
total height of above 12 feet. On the top of the entablature are metal
standards for tapers.
Father Bonanni, who wrote in the seventeenth century, describes the
chapel as arranged in the following manner:—1. The altar. 2. The pope's
throne. 3. The benches for the cardinals and prelates. 4. An enclosed
space for the religious and officers of the pope's court. 5. A sort of
balustrade which separates these portions from the laity: at the top of
this balustrade are placed four, six, or seven tapers, according to the
solemnity of the time.
The term balustrade has been usually applied by old writers to screens,
and must not be understood in the modern acceptation, of signifying a
sort of rail hand high; in this instance we have a clear proof to the
contrary, for the screen termed a balustrade is still standing, and,
with the exception of the style of pillars and mouldings, is very
similar to those erected in Pointed churches. Trevoux, in his great
dictionary, has the following explanation of the word: "Balustre also
signifies those small _pillars_ to shut off the alcove in a room, or the
chancel of a church or chapel. Columellæ, Cancelli, &c." In this sense
they are always to be understood when mentioned by old writers in
reference to church architecture. Low balustrades, or rails, were
unknown to antiquity. The enclosures were always of a sufficient height
to prevent persons getting over them, and the low rails round altars,
are, in England, a pure Protestant introduction, and originated in the
necessity of preventing the gross irreverence offered by the Puritan
party to the holy tables, on which they frequently sat during the
sermon. If the word balustrade as used by French and Italian writers, be
not thoroughly understood, it must lead to a misconception of the old
arrangements. Pistolezi, in his great work on the Vatican, describes
this screen as a balustrade; his words are as follows:—"La Capella—e
divisa in due spartamenti, il minore, che della Porta alla _Balustrata_
de marmore si estende, _serve per i Laici_," &c.