Ravenna possesses several circular buildings, almost as interesting as those of the capital; the first being the baptistery of St. John belonging to the original basilica, and consequently one of the oldest Christian buildings of the place. Externally it is a plain octagonal building, 40 ft. in diameter. Internally it still retains its mosaic and other internal features added in the 5th century, which are singularly elegant and pleasing. Its design is somewhat like that of the temple at Spalato, but with arcades substituted everywhere for horizontal architraves; the century that elapsed between these two epochs having sufficed to complete the transition between the two styles.
429. Plan of St. Vitale, Ravenna. (From Isabelle.) Scale 100 ft. to 1 in.
Far more interesting than this is the great church of St. Vitale, the most complicated, and at the same time, perhaps, the most beautiful, of the circular churches of that age. In design it is nearly identical with the church of St. Sergius at Constantinople (see Woodcut No. [311]), from which it was undoubtedly copied, and probably by Greek artists from that town. It was built in the reign of Justinian by St. Ecclesius, archbishop of the see, and was consecrated in 547, eight years after the taking of Ravenna by Justinian’s generals. The principal difference of the plan lies in its being enclosed within an octagon instead of a square, as in St. Sergius, probably to mask the irregularity of the main entrance from a street which did not run in the direction of any of the cardinal points. The recesses are loftier in proportion than those of St. Sergius, and in the lower storey arcades take the place of beams. The aisles being covered with timber roofs, it was necessary to raise the walls of the octagon higher than those of St. Sergius, and small arches take the place of the usual pendentives: the springing of the dome, which is 50 ft. in diameter, is on the level of the sill of the windows the arches of which therefore form penetrations into the dome.
430. Section of St. Vitale, Ravenna. (From Isabelle.) Scale 50 ft. to 1 in.
The church is built in bricks with thick mortar joints, the dome being constructed in an ingenious manner with hollow pots fitted the end of one into the mouth of the other; the lightness of this vault has enabled the builders to dispense with the immense arches and buttresses found in St. Sergius and in Sta. Sophia. Similar construction with pots had been employed in the East for domes and roofs,[[291]] and they form as permanent a method as stone itself, in addition to the stability, facility of construction, and lightness which such an expedient affords.
431. Capital in St. Vitale, Ravenna.
Internally a good deal has been done in modern times to destroy the simplicity of the original effect of the building; but still there is a pleasing result produced by alternating the piers with circular columns, and a lightness and elegance about the whole design that render it unrivalled in the western world among churches of its class. This seems to have been admitted by its contemporaries as much as it is in modern times. Charlemagne at all events copied it for his own tomb at Aix-la-Chapelle, and the architects of many other circular buildings of that age appear to have derived their inspiration from this one.