Roman Glass, Glass Technology

For reconstruction of techniques of enameling of the adornments from the Bryansk hoard, the data on both provincial Roman production and modern enameling were taking into account. To fill most of the needles, powdered enamel was used. In the needles of large sizes, the ground layer could be clearly seen in some places (Tab. LV: 9). Disc-shaped needles of a small size were often filled with smoothed pieces of glass (Tab. LV: 1-5). At the final stage of treatment, the surface of enamel needles was ground and polished. Triangular fibulae (Nos. 78-80) differ in the technique of filling. In the needles of disc-shaped projections, the surface of the enamel (which are pieces of glass) protrudes over the edge of the metal base, its surface is not treated as carefully as on the other adornments (Tab. LV: 1-3). The fibula No. 80 has a smoothed piece of glass which is also used to fill the triangular field on the foot (Tab. LV: 7). The fibulae Nos. 78 and 79 are distinguished by a poorer finish quality of enamel inserts.
A series of adornments with polychrome enamel fields is of particular interest. Study of their manufacturing techniques allowed to establish that the craftsmen used a wide range of technological methods. Among them are the decor in the form of drawn applied elements (Tab. LVI); the decor, applied as a wet powdered enamel (Tab. LVII: 10-14); filling of fields without metal bars with ground down pieces of glass and powdered enamel of different colors simultaneously (Tab. LVII: 1-9), etc. Differences in technology of manufacturing of various elements of adornments show that the craftsmen paid special attention to the difference in melting temperatures of enamels of various colors, as well as features of color formation in red and orange opaque glass. The use of complex enameling techniques in combination with hot glass working allows us to come to a conclusion that the adornments of the Bryansk hoard have been made not by Barbarian, but by late antique (most probably provincial Roman) craftsmen by commission for the local population. Furthermore, raw materials for enamels could not be limited to imported beads present in the Dnieper region. Therefore, this production has been specially provided with semi-finished products (raw glass, tesserae, glass cullet), which was not easily accessible in the region. Nevertheless, the style of East European champlevé enamels developed, of course, independently of provincial Roman production. That could be due to the use of other forms of adornments, often with enamel fields (first of all – monochrome) of larger sizes. This circumstance could explain the absence of their direct prototypes among enamels from the territory of the Empire. One of the techniques – the use of applied drawn elements does not find parallels among the provincial Roman enamels as well.

Dip moulds from Komarov (Middle Dniester, Ukraine) for producing ribbed blown glass vessels provide important information on chronology of the workshop and some kinds of its production allowing evaluation of the informative value of archaeological collections for solving the tasks. Based on these finds, E.M. Stern suggested dating the workshop back to the period not earlier than the mid-4th c. This date, from the mid-4th c. to the beginning of the Hun period, is to be confirmed by the archaeological context of one of the finds, as well as by the chronological position of ribbed vessels, originated from the Chernyakhov culture area, and other independent data on the chronology of the workshop. A find of a ribbed moil justified the production of ribbed vessels in the workshop; nevertheless, the latter does not reflect in other materials from the site. It is likely that ribbed vessels were not popular among the local population. The extreme rarity of such finds at the site might also be the result of collecting glass for recycling; this practice was actively applied in the Komarov workshop. It might be suggested that some other kinds of vessels made there remain out of view of the scholars.

The chemical composition of a series of Eastern European enamels from the Bryansk hoard from the third century AD and other sites was studied using scanning electron microscopy with energy-dispersive spectroscopy (SEM-EDS) and electron microprobe analysis (EPMA)
techniques. Red opaque glass is homogeneous compositionally, suggesting not only common manufacturing traditions but also identical types and sources of raw materials and, consequently, a single origin. The glass is made in the Roman tradition of enamelling, which appeared in the mid-first century AD, as was the case with orange glass. The difference in the lead content in glass of different colours, which determines the melting temperature, allows the reconstruction of polychrome enamelling techniques.

The Bryansk hoard of the late 2nd – 3rd centuries, found in the South-Western part of Russia, is an outstanding complex of East European enamelled objects. This style of “Barbarian” enamels has spread in the Baltic region and in some areas of the Eastern Europe from the mid- or late 2nd to the 3rd centuries. The manufacturing technology of at least polychrome enamelled items from the hoard strongly suggests the participation of provincial Roman craftsmen in the production of such jewellery, in spite of its distribution area and a very “Barbarian” appearance.

The chemical composition of Bryansk hoard enamels (late 2nd-3rd century) has been investigated by SEM-EDS and EPMA methods. Raw materials and technological additives are characterized, and the sources of manufacturing traditions are revealed. The differences in the compositions of enamels of different colors have made it possible to reconstruct some procedures of enameling objects with polychrome fields.

The paper compares manufacturing techniques, evolution of styles and
changes over time in the spread of provincial Roman and East European champlevé enamels. Identical production techniques, stylistic and chronological similarity in development of both styles, the same period of the most extensive use, and, more importantly, parallel decline in the production of champlevé enamels of Roman continental provinces and the East European enameling suggest that these production traditions were closely related to each other throughout the entire period of their use. Penetration of the Chernyakhov population into the territory occupied by the Kiev culture in the Dnieper region was not the only, and, probably, not the most important reason why ‘Barbarian’ jewelry with enameled fields disappeared.

This paper seeks to explore some of the possible connections between three late antique strands of glass technology and application in the Near East: windows, lighting, and finally, re-cycling. Glass has long been acknowledged to have influenced two major innovations in the use of internal space within the Roman world - once, in the early Empire, when window-panes were first applied to bath-houses to maintain humidity and temperatures whilst casting light into dark interiors, and again, in the 4th c. A.D., when oil-lights made of glass were finally adopted as an effective medium for ceiling-lighting.

Three whole glass bottles and six vessel fragments (Fig. 10:1–9) were found in Tombs F1 and F3. Remains of furnace debris from glass manufacturing and chunks of raw glass were also discovered. The whole vessels represent familiar types from burial assemblages that were exposed in the region and date from the Late Roman–Byzantine periods (fourth–sixth centuries CE). The industrial debris is from furnaces used in the manufacturing of raw glass, such as those that operated in the region of Apollonia and its surroundings during the Byzantine and Early Islamic periods (Roll and Ayalon 1989; Gorin-Rosen 2000:54–55; Tal, Jackson-Tal and Freestone 2004; 2008).

This paper discusses the development of Roman antimony decolourised natron glass, its dominance, and subsequent decline, using new trace element data for colourless glass found in Britain. Experimental glasses are used to investigate the influence of different proportions of raw materials (particularly the ratio of natron to calcium carbonate) on the resulting transparency or opacity of glass when antimony is added. Focusing on the 1st to 3rd centuries AD, the study has found that (1) There are chronological differences in antimony colourless glass compositions including (a) some early vessels have abnormally low calcium, aluminium and barium levels; (b) 1st/mid-2nd-century AD vessels in Britain may also contain up to 0.6 wt% lead oxide whereas mid-2nd/3rd-century AD vessels contain less than 300 ppm, and (c) the antimony content tends to decline over time. (2) These developments can be linked to production and recycling practices; but trace elements suggest that all of these antimony colourless glasses share an origin, probably Egypt. (3) Crucially, production of experimental glasses illustrates the inherent suitability of a sodium-rich, calcium-poor base glass composition for making antimony colourless glass, as it readily dissolves added antimony; conversely lower-sodium, higher-calcium glasses start to form opacifying calcium-antimonate crystals with the same quantities of antimony. Thus, the sodium-rich, calcium-poor glass composition from Egypt was ideally suited for decolourising with antimony and formed a water-clear glass. The calcium-rich Syro-Palestine glasses were more easily opacified with antimony to make opaque glass, but were decolourised with manganese, not antimony.

The paper presents a bronze figurine of an eagle from island of Berezan. It comes from badly described object cut by a test-trench of 1902. An approximate location of the trench is defined by interpretation of an excavation map from archive of OAM. Similar (but not identical) eagle statuettes had been discovered in Olbia, in sacred place on Gurzuf Sedlo mountain pass and some other sites. Perhaps, the complex included a fragment of glass bowl Ist century A.D. Both artifacts allow to take a complex to the Ist century A.D. / Статья посвящена введению в научный оборот орнитоморфной бронзовой фигурки из археологических работ на острове Березань начала XX века. Результаты анализа находки и объекта, в котором она была обнаружена, могут быть важным источником для изучения истории населения Нижнего Побужья в первом веке новой эры.