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.