tion from Pliny, already given. Sectile work in glass is found in some examples of Christian art, but mar- ble is more common, altliounh tlie tessellated work in the same buildings may l>e of ttlass. This use of mar- ble proliably arose from the dci-ay in the niaiuifactiiri' of the special plass and the ditliculty of culliiii; and
ic OF "The Tiger and Heifer" (a. b. 317) Preser\'ed in S. Antonio Abbate, Rome
grinding it exactly to the forms. Sectile in marbles is foimd in Santa Sabina, Rome (42.5-4.50); in the baptistery of the cathedral, Ravenna; in San Vitale, Ravenna (sixth century) ; at Parenzo (sixth century) ; in Sancta Sophia at Constantinople and at Thessalonica, (sixth centurv-); its use thus has been continuous ever since, and was an especial feature of the Renaissance.
The portion of this theme of the greatest impor- tance in the present article is that concerned with the glass mosaic of Christian churches. The initial steps by which it gradually emerged from Pagan art are in a measure lost, for it rises suddenly like a phcenix from the ashes, complete, entire in its ma- nipulation, whilst the character of the subjects and designs represented bespeak the traditions adopted by the artists of the catacombs. Mosaic, as far as one can at present ascertain, became a vehicle of Christian art in the fourth century. The earliest examples, such as those of the first basilica of St. Peter and St. Paul, are all destroyed. In the church of St. Costanza on the Via Nomentana there still re- mains interesting work. We have also preserved in the Chigi Library some mosaic from the catacomb of Cyriacus. A mosaic of St. Agnes in the catacomb of St. Callistus was, however, so decayed, that the existing picture was painted over it in the sixth cen- turj'. Other mosaics have been found on sarcophagi in the catacombs. The most interesting early work is, however, that now existing in the apse of the church of St. Pudentiana (398) [Fig. 7]. It has been much restored in parts and was added to in 1588, but the design remains. Of the same period is the mosaic in the baptistery at Naples. It is uncertain whether the apse of St. Rufinus's is of the fourth or fifth century, but it is interesting as early work.
A great impetus to the art occurred when Constan- tine, in establishing himself on the throne of Byzan- tium, commenced to give his capital an imperial ap- pearance as far as art was concerned. He gathered together artists from all celebrated centres, and gave to them special legal and civil or civic favours. Of the works carried out by them, the mosaics of the church of St. George at Thessalonica in many cases yet occupy their original position. The nave of St. Mary Major's in Rome still retains some of the fine mosaics placed there in the fifth century (4.30-440) and the churches of St. Sabina (422-433), of St. Paul without the walls, and of St. John Lateran were also BO decorated in the same era (446^02). St. Paul's, destroyed by fire in 1823, has since been restored and
little of the original remains. What remains of the original mosaics of St. John Lat eran's dates from 432- •140. The mosaics of the chun-h of Saints Cosmas and Daiiiian (526-530) wererestdicd in KKiO. .\t Ravenna the mosaic work in the various clnirclu's is the finest of ils iicriod. That in the biiplistery of the cathedral (irdicated to St. John the Baptist [Fig. 6] is an cspciially good example, the church being originally built at the end of the fourth century but burnt in 434. The mosaics of the Mausoleum of Galla Placidia (450) are also of excellent design and work- manship. Unfortunately some of these have been restored with painted stucco. Those in the chapel of the archiepiseopal palace and of the church of St. John the Evangelist are too of this period. The mosaics of the cathedrals of Novara and Aosta and the chapel of St. Satira in St. Ambrose's, Milan, are also of the fifth century. In France at Nantes, Clermont, and Toulouse historians record the placing of mosaics which no longer remain.
The greatest works of the sixth century, and per- haps the greatest of all mosaic works in extent, were those carried out under the Emperor Justinian in Sancta Sophia, Constantinople. In 533, a fire de- stroyed what then existed, but in a quarter of a cen- tury the restoration was commenced under Anthemios and Isidore, who, it is recorded, employed ten thou- sand builders, craftsmen, and artists. The colour is subdued, and the design and execution good of its period. Justinian also caused the church of Sancta Sophia at Thessalonica to be built, and decorated with mosaic. Further great works were executed at Ravenna at the same period. After the conquest by Belisarius in 539, it became the residence of the exarchs in 552, and S. ApoUinare Nuovo [Fig. S], S. Maria in Cosmedin (553-566), S. Vitale (524-534) [Fig. 91, and S. Apollinare-in-Classe (534-549) were lauilt and filled with mosaics. It will be observed that these churches were commenced under the Ostrogoths and finished under Justinian, who prob- ably had the mosaics executed by local artists.
Friirii HipMi i n of ( ilhe inl H n ii
The namco of Euo^riuS, P^uluo, Stat^us, Stephano, etc. are recorded. Greeks may have worked with them. The design of the work in St. ApoUinare Nuovo is new to western art and consists of two pro- cessions of figures, all very similar, which extend along the whole of the nave over the arches. It is curious that in the mosaics of the Adoration of the Magi, the Magi wear the same Persian costume we find