I may say at once that the Romans, as far as we know, never attained to any great success in this method of decoration. Its full development was reserved for the Saracens of the thirteenth and fourteenth centuries. This is indeed the one important advance made in the artistic manipulation of glass since ‘the palmy days of Rome.’
Not but that the Romans, and probably to some extent the Phœnicians and the Alexandrian Greeks before them, did not draw and paint upon their glass; but if we may judge from the rare and fragmentary examples that have survived, they were unable to obtain much decorative effect by this means; again, the very poverty and the paint-like quality of such enamels as they used, have doubtless in many cases led to their total disappearance from the surface of the glass.[[36]] The painting on the cup-like lids of the little bowls from Cyprus I have already mentioned. On a few fragments of thin glass from Egypt, draped figures have been painted in opaque colours. Perhaps the nearest approach to an effective use of enamel colours may be seen on two little cups found in graves of the fourth century at Varpelev, in Denmark. These Scandinavian tombs have yielded many interesting pieces of glass, as well as some bronze vessels—possibly booty brought home from marauding expeditions. The designs on these cups (they are illustrated in the Proceedings of the Copenhagen Antiquarian Society, 1861) are thus described by Mr. Nesbitt: ‘On the larger one are a lion and a bull, on the lesser two birds with grapes.... The colours are vitrified and slightly in relief—green, blue, and brown may be distinguished.’ (Slade Catalogue, p. xvi. See also some account of glass from these and other Scandinavian tombs in Montelius and Reinach, Les temps préhistoriques en Suède.)
But the most important and the best preserved example of enamelling on glass is to be found in a small bowl, probably of the third or fourth century, preserved in the treasury of St. Mark at Venice. To this important collection I shall have more than once to return.[[37]] The little bowl in question—something over three inches in height—is of a translucent glass of a winy or purplish colour. The seven larger medallions that surround the body are filled with mythological subjects in a fairly good classical style; the pale buff-coloured figures on a black ground imitate an onyx cameo. Each medallion is surrounded by a circle of rosettes of brilliant colours—blue, red, purple, and white. The angular spaces are filled by smaller medallions, each containing a head, and the remaining ground is occupied by a tracery of gold. According to the Canonico Passini, this decoration is in very slight relief, and is executed in what can scarcely be regarded as a true vitrified enamel. The bowl has been mounted at a later time in a light setting of silver gilt with elegant winged handles. But what is more curious, at some time previous to the addition of the mounting, a band of white ornament, resembling cufic letters, but apparently illegible, has been painted round the inside just below the rim, and again outside the base. Much of this later ornament has been abraded, although the original decoration is well preserved, and I think that this fact is an argument in favour of the earlier work being after all of the nature of a true enamel fixed by fire. I describe this bowl here as I cannot see any trace of Byzantine influence in the purely classical medallions.[[38]]
Finally, on a few of the gilt catacomb glasses, of which I shall speak shortly, a little coloured enamel is sparingly applied here and there, especially in the draperies.
Engraved and Sculptured Glass
There remains one large division of Roman glass which I have purposely left to the last. In this are comprised the engraved and sculptured pieces, the bulk of which belong to a late time; indeed we may pass from work of this kind to glass that is purely Byzantine in character without any violent transition. But to return for a moment to examples taken from quite the other end of the series, we have seen that the glass bowls that are associated with Alexandrian-Greek and early Roman times are mostly finished by a cutting-tool on some kind of lathe. In the case of the bowl of white glass from Canosa in the British Museum, closely imitating in form the well-known scyphos of the Greek potter, the handles are apparently carved out of a solid mass (cf. p. [46]); a very similar bowl in the Charvet collection, said to have come from Cumæ, is illustrated by Froehner. Still more interesting is the large shallow bowl or dish of white glass in our national collection; this is again from a tomb at Canosa. A ring of some twenty spurs, each about half an inch in height, arises from the outer margin; these spurs are carved apparently out of the solid glass. A large rosette cut in low relief, representing a full-blown lotus flower, covers nearly the whole of the surface. With this work we may compare the rosettes, much more rudely carved, it is true, on the base of some very similar bowls of late date from the Rhine country.
Of quite a different character is the carving on those earlier vessels of which we may take the well-known Portland vase as a type. Here the delicate sculpture in low relief takes us back to the cameos of the Hellenistic Greeks, which, as we have seen, were often executed in a glass paste. But few specimens of work of this kind have come down to us—some half-dozen in all—and of these only two are perfect. The body of these vases is formed by two or more superimposed layers of glass, of which the outer one, generally of an opaque white, is ground away by the wheel of the engraver, leaving a design in low relief upon a basis of blue or other colour.
The most famous example of this class is, without doubt, the Barberini or Portland vase, a two-handled urn found towards the end of the sixteenth century in a marble sarcophagus at the Monte del Grano, a lofty tumulus some three miles to the south-east of Rome. Whether the tomb from which the urn was extracted was that of the Emperor Alexander Severus, who was killed in the year 225, is not of much consequence, for the vase itself is certainly of an earlier date. The figures in this case stand out upon a dark blue ground—we need not dwell upon the interpretation of the subject. As Wedgwood long ago pointed out, a rich and almost pictorial effect is given by cutting down the white layer in places nearly, but not quite, to the blue base which then shows through a film of the slightly translucent white paste—an effect, by the way, that is almost lost in the imitations of this vase made in the opaque Wedgwood ware. A curious point about this vase is the fact that the decoration is continued over the circular base on which it stands. This medallion-like space is filled by the bust of a youth with a Phrygian cap wrapped in voluminous drapery. There is some doubt, however, whether this medallion is of so early a date as the rest of the vase.[[39]]
Almost identical with the Portland vase in technique and material is the amphora of onyx glass, carved as a cameo in low relief, which was found in 1837 in a tomb on the Strada dei Sepolcri at Pompeii. In this case we have a limit—a terminus ad quem—for the date, the middle, that is to say, of the first century of our era. But the work may well be of a somewhat earlier time than this. The decoration is distinctly Alexandrian in character. Notice especially the band at the lower part with the sheep feeding under trees—in this we are at once carried back to the pastoral poetry of Sicily. It will be observed that the vintage scenes with the little naked ‘putti’ are placed under the handles, while the place of honour is reserved for the beautiful design of vine-branches, masks, and birds. The highly developed technical skill required, especially in the preliminary blowing and ‘casing’ of the glass, is, however, an argument against throwing back too far the date of vases of this class.
Some fragments of another vase of a similar character were found at Pompeii at a later date; the pieces after passing through various hands are now in the British Museum, where they have been united to form (with extensive gaps) an œnochoë or jug, known as the Auldjo vase, from the former owner of most of the fragments; in this case the decoration of the parts preserved consists chiefly of vine and ivy leaves. There are at Naples many fragments of onyx glass equal in beauty and skill of execution to these well-known vases. Among these, the half of a patera decorated, on a dark blue ground, with a mask surrounded by the leaves of the Oriental plane, is of exceptional merit. In other cases the parts in relief seem to have been cast separately and fixed on to the surface, a technical process of quite another nature.