Achaeometrical Research in Hungary II., 1988

ANALYSES - GLASS - Edit MESTER - István SZABÓ: Research of medieval glass vessels and glasshauses in Visegrád and Diósjenő

The chemical composition of glass samples, remains of refractory pots and raw materials showed that glass-workers had been using polluted materials and lower temperatures during the melting of glass in these glasshouses than was characteristic of glass finds imported from Venice. The potassium-oxide content is typically high in the composition of glassware prepared at Visegrád and Diósjenő due to the melting technology applied, that resulted in products of lower chemical durability (Fig. 17-18) Cheap household and industrial glass vessels were made in these glasshouses. Similar glass remains have been excavated in the neighbouring countries as well. Individual local ware and the imitations of the imported products were probably made in these glashouses. The glass material of such products corroded considerably during centuries. The inhomogeneity of glass materials enhanced the weathering process (Fig. 19-20). Further examinations are necessary in order to provide more detailed answers to these questions. In the future we intend to excavate and analyse additional glasshouses in Hungary. 5. Summary Generally speaking, a pronounced duality of quality and shape is visible on the glass vessels excavated in the palace and castle of Visegrád. Imported goods of high quality occurred most frequently between the second half of the 14th and the first half of the 15th century. They include Venetian small prunted goblets, bowls and biconical flasks. Merchants ofthat period brought them to the market in complete collections as is shown by the great number of fragments found near the Roman Catholic church of Visegrád. Imitations of the imported fine glassware used during royal celebrations soon appeared on the market. It was less elaborate and in general of lower quality. The results of material studies and of the excavations carried out at the glasshouses suggest that the majority of vessels covered by a brown, discoloured corrosion layer had been made in Hungarian workshops. The compositions and shapes of glassware found in the glasshouses of Visegrád and Diósjenő were also observed among the vessels found in the palace and of the Lower castle in Visegrád (for example flasks with necks articulated with a simple ring, panes of glass etc.). These imitations stand out among the glass finds from the end of the 15

th century, due to their unique shapes and similar compositions. However, a diachronically improving quality can also be observed. Considering the find material that was discovered in the area of the castle, especially from the 15

th and 16

th centuries (not taking into account some imported goblets), it is possible to observe that the quality of Hungarian products improved under the influence of the German and Bohemian glass industry (for example prunted goblets, cups, gurgling flasks, jugs etc.). The complete inventory of glass finds from the royal palace of Visegrád shows by the great variety of vessels as well as by their stylistic richness, that the royal court enjoyed feasting in splendidly furnished buildings at lavishly set tables. We tried to distinguish between the types of Hungarian and imported glassware with the help of both scientific examinations and the excavations of glasshouses. Many local investigations are still needed in order to establish the provenances of the raw materials, the routes of trade and to identify additional glasshouses. We intend to expand this work in the near future and publish its results. 106