Engraved gems are not the only examples of Roman work in precious metals. Amongst the portraits of the first dynasty none i are finer than the small head of Agrippina the younger in the British Museum in plasma (root-of-emerald), and the lovely head of Tiberius in turquoise, acquired by the British Museum during the World War, from a soldier, who found it in Egypt. Vases, again, were carved in precious stones, such as the famous onyx vase at Brunswick (Furtwangler, op. cit., figs. 185-88) with reliefs relating to the mysteries of Eleusis, and the smaller, but finer, onyx vase in the Berlin museum (Furtwangler, op. cit., figs. 183-184), representing the lustration or baptism of a prince of the Julian line—a rock surmounted by a small temple recalls one slab of the Ara Pacis, and the work seems of Augustan date.
As mentioned before, coloured glass was used as a substitute for gems, and it is to the school which produced the cameos of the early empire that we owe the vases in white and blue glass of which the Portland vase in the British Museum is a famous example. Pompeii furnishes a second in the amphora, decorated with vintage scenes, in the Naples museum.
We must also class amongst the fine arts that of the die-sinker. Not only are the imperial portraits found on coins worthy of a place beside the works of the sculptor, but in the medallions of the 2nd century A.D. we find figure-subjects, often recalling those of contemporary reliefs, treated with the utmost delicacy and finish. Later lead medals often reproduce landscape motives and actual views; e.g., medal of Diocletian, in Paris, with view of a city, its river and bridge; medal of Constantius Chlorus, found in 1922 near Arras, with the Thames and the port of London; medal of Constantine with the famous gate of Trier. The fine bronze medallion of Valens and Valentinian, enthroned side by side in frontal pose, shows that the art of the medallist was still vital in the 4th century A.D.
Ivory was a favourite material with the Romans, as it had been with the Etruscans. It was worked both in the round and in relief and often used for the adornment of furniture. A head of 1st century date—probably Augustus—in the Stroganoff collection, and another representing a personage of mid 3rd century date, in the British Museum, rank with the best Roman portraiture. The series of consular and other diptychs are discussed in a special article (DIPTYCH). Among them are masterpieces like the mag nificent Symmachorum-Nicomachorum diptych, one leaf of which is in the Victoria and Albert Museum and the other in the Cluny Museum at Paris. Diptychs also largely helped to keep por traiture alive; fine examples of this type are the diptych of Probus at Aosta with the double portrait of Honorius (Plate III., fig. o) ; that of Felix, of the year A.D. 428, in Paris and that of Boethius, consul in A.D. 487, in the museum of Brescia.
Of the purely industrial arts it is unnecessary to speak at In the last century of the republic a flourishing manufacture of red-glazed pottery was established, with its chief centre at Arret ium (Arezzo) ; the signatures of the vases enable us to distinguish a number of workshops owned by Romans who employed Greek or oriental workmen. The repertory of decorative types reflects the cross-currents of classicism and naturalism which were con tending in later Hellenistic art. In the 1st century A.D. the Italian
fabrics were gradually driven out of the market by those of Gaul, where the industry took root in the Cevennes and the valleys of the RhOne and the Allier ; and before long north-eastern Gaul and the Rhineland became centres of production in the various minor arts, which continued to flourish until the breakdown of the imperial system in the 3rd and 4th centuries A.D. Glass, though made in quantities for the Roman market, was usually of foreign manufacture, probably Syrian. The subject is fully treated in Kisa, Das Glas im Altertum.
With only limited space at our disposal, we have confined our selves in the above section to monuments in Rome, only going outside the capital for examples of exceptional importance. The products of local or provincial art and the special problems which they raise cannot be treated here, though some clue to the litera ture of the subject will be found in the bibliography. The Museo del Impero Romano affords a well-arranged survey of Roman provincial art; it contains, along with much that is new, most of the objects from the Exhibition of the Roman Provinces held in the Baths of Diocletian in 191i, an account of which by E. Strong appeared in the 1st volume of the Journal of Roman Studies.
It may be said that as the establishment of the Roman empire gave a political unity to the ancient world, and acceptance of Christianity by its rulers assured the triumph of a universal religion, so the growth of a Graeco-Roman nationality, due to the freedom of intercourse between the subjects of the emperors, led to a unity of culture which found expression in the art of the time. Yet no sooner was the fusion of the elements which con tributed to the new culture complete than the process of disrup tion began, which issued in the final separation of the Eastern from the Western empire. In the first, the oriental factors, which produced a gradual transformation in Graeco-Roman art, definitely triumphed ; and the result is seen in Byzantine art. But in the West it was otherwise. The realism native to Italy remained alive in spite of the conventions imposed upon it ; the human interest asserted itself against the decorative. Therefore, the Christian art of the West is the true heir of the Roman, and, through the Roman, of the classical tradition. As we have seen, Roman art in its specific aspect was an historical art ; and it was for this reason eminently fitted for the service of an historical religion. The earliest Christian art whose remains are preserved is that of the catacombs; but though not devoid of technical merit (on this point see A. della Seta, Religion and Art, p. 331 seq.) this art is dominated by the single idea of deliverance from the grave and its terrors, whether this be conveyed by scriptural types or by representations of paradise and its dwellers. Not until the Church's triumph was complete could she command the services of the highest art and unfold her sacred story on the walls of her basilicas; but, when the time came, the monumental art created by the demands of imperial majesty was ready to pass into the service of Christianity.