Of the other examples the oldest was the finest. This great basilica was erected in the reign of Constantine, close to the circus of Nero, where tradition affirmed that St. Peter had suffered martyrdom. It unfortunately was entirely swept away to make room for the greatest of Christian temples, which now occupies its site; but previous to its destruction careful measurements and drawings were made of every part, from which it is easy to understand all its arrangements—easier perhaps than if it had remained to the present day, and four centuries more of reform and improvements had assisted in altering and disfiguring its venerable frame.
As will be seen in the plan (Woodcut No. 274), drawn to the usual scale, it possessed a noble atrium or forecourt, 212 ft. by 235, in front of which were some bold masses of building, which during the Middle Ages were surmounted by two belfry-towers. The church itself was 212 ft. in width by 380 in length, covering, without its adjuncts, an area of above 80,000 English feet, which, though less than half the size of the present cathedral, is as large as that covered by any mediæval cathedral except those of Milan and Seville. The central aisle was about 80 ft. across (about twice the average width of a Gothic nave), and nearly the same as that of the basilica of Maxentius and the principal halls of the greater thermæ. For some reason or other this dimension seems to have been a modulus very generally adopted. The bema or sanctuary, answering to the Gothic transept, extended beyond the wails of the church either way, which was unusual in Romanesque buildings. The object here seems to have been to connect it with the tombs on its north side. The arrangement of the sanctuary was also peculiar, having been adorned with twelve pillars supporting a gallery. These, when symbolism became the fashion, were said to represent the twelve apostles. This certainly was not their original intent, as at first only six were put up—the others added afterwards. The sanctuary and choir were here singularly small and contracted, as if arranged before the clergy became so numerous as they afterwards were, and before the laity were excluded from tins part of the church.
The general internal appearance of the building will be understood from the following woodcut (No. 275), which presents at one view all the peculiarities of the basilican buildings. The pillars separating the central from the side aisles appear to have been of uniform dimensions, and to have supported a horizontal entablature, above which rose a double range of panels, each containing a picture—these panels thus taking the place of what was the triforium in Gothic churches. Over these was the clerestory, and again an ornamental belt gave sufficient elevation for the roof, which in this instance showed the naked