HISTORY OF GLASS-MAKING.

XVII

in Bheinlande , Heft xxxvi., taf. 3), shews such an arrangement; of the smallcoloured medallions with which this was studded about twelve remain.

In other specimens, such as the fragment No. 120, and the remarkable diskfrom Cologne (No. 317), the gold leaf seems to have been applied to the surfaceof the glass, and not protected by a second coating. Such specimens must havebeen, however, peculiarly liable to injury. Enamelled decoration was alsooccasionally added, as in the case of No. 317.

The processes which remain to be mentioned are those in which decorativeeffect was obtained by variety of form, and these are the two which Pliny hasindicated in the words “ aliud tlatu figuratur,” and “ aliud torno teritur,” the firstincluding blowing and moulding, the last grinding and shaping on the wheel.

Cameo glass and that later kind in which portions are only attached to theground at points, ought, in strictness, to have been spoken of under this head,but reasons of convenience have led to the arrangement adopted.

Variety of form was given by several processes connected with that of blowing,for instance, by moulding with pincers or other tools, by forming projecting ribson the sides (now called pillar moulding), as well as by the use of moulds,probably of metal, into which the glass was either blown or pressed. Manybeautiful examples of these processes will be found in this collection; amongthose blown into moulds were bunches of grapes, dates, and human heads, ofvarious colours (see Plates V. and VI., also Section C. Roman Glass). Masks andornaments were likewise often made in a mould and attached to vases, etc.; andone maker has recorded his name and abode, Artas Sidon, both in Greek and inLatin, the words appearing' in relief on the handles of cups, as if formed by theuse of pincers on which they had been engraved; (see No. 199, and Fig. 47).

An elegant long-necked bottle, in the British Museum, seems to have beenblown within a cage of wire; this process has given to its surface the littlerounded elevations we see in the glass, which is now so common, and oftencalled “kinkled.”

A great number of vessels of various forms, whether cups, paterae, or vases,were, after they were blown, finished by the wheel, and afford beautiful examplesof skill in manipulation, portions being often much undercut. The artisans knownas diatretarii probably executed this work.*

The whole surface was also sometimes cut, not as in modern times intoprojecting pyramids, but into a series of indentations of a curvilinear form, as Figs.37 and 38. In another class of examples, figures and ornaments were engraved inshallow intaglio; this was evidently done with tlie lapidary’s wheel, and in a fewinstances ( e.g ., a cup in the Museum at Cologne) details were added with the pointof a diamond or other hard stone. Work of this kind is usually bad both in styleand in execution, and evidently belongs to a late date (see No. 169); a fragment

* They are mentioned in the Codex (Lib. x. tit. 64) in the ordinance of Constantine II., a.d. 337.Biatretum occurs in the Digest of Ulpian. See Facciolati, sub voce.

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