THE DOME CHURCHES.
THE important early surviving illustrations of the dome churches are the chapel built by Charlemagne, already mentioned (page 161), the Church of St. Mark at Venice (page 173, Fig. 95), the Church of San Vitale at Ravenna (Fig. 106), the Church of St. Sophia at Constantinople, and possibly the "Dome of the Rock," or Mosque of Omar, at Jerusalem. It was the theory of the English architect, Fergusson, that this was a Christian church of the fourth century, built over the supposed site of the Holy Sepulcher.* The present dome, the exterior decoration of porcelain tiles, and the inserted pointed-arch windows are Arab reconstructions. Two baptisteries at Ravenna ( fifth century) and the Baptistery of St. John Lateran at Rome (fifth century) are smaller buildings of the same general type.
Among the buildings named and illustrated those are most obviously available as indications of the type which are most obviously of a radiating plan. The domed ceiling was naturally used for such a building and herein lies the distinction as compared with the long perspective view of the basilicas. It was from the great domed apartments of the Roman baths that this plan of construction was adopted and even their name was retained. They were called "baptisteries," that is to say, baths; and the title of baptistery, or bath, survived as applied to the churches copied from them.
The name and plan subsequently became distinctive in____________________