Kovács Petronella (szerk.): Isis - Erdélyi magyar restaurátor füzetek 17. (Székelyudvarhely, 2017)
Domokos Levente - László Károly: A berethalmi evangélikus templom sekrestyéjében álló kandalló restaurálása
is able to keep good condition between the applied two layers of glass (the glass support above and cartellina, the thin covering sheet of glass, on the top). The methods of mercury gilding have been known and used for decorating various objects, mainly metalwork, for more than two millennia. There are several versions of the making in the historical knowledge, apart from amalgam gilding, such as cold mercury gilding, powder gilding, and the so called vermeil technique. The mural mosaic decoration in the former Royal Basilica of Székesfehérvár/Alba Regia is likely earlier than all the known mural paintings remained from the Middle Ages in Hungary. The medieval masters working in the Royal Basilica distinguished between the traditional gold tesserae (composed by the following three hot fixed layers: poured glass support, thin beaten gold leaf, thin layer of blown glass as a covering) and gold mosaic version type “B”, defined and tested by the author (poured glass support, gold and mercury contented layer, and thin cartellina). A geometric patterned mosaic fragment came to light by archaeological excavation, contains both types; the cross in the middle is made of traditionally produced gold tesserae, but the “B” type metal foiled ones compose the background. The results of the microscopic studies (about the structure, thickness and appearance of the metal layer) were supplemented by the XRD and handheld XRF measurements by István Sajó. The main result is the detection of mercury, which indicates a different variation of producing gold tesserae not to be mentioned in the written sources. It is significant because the detection of the different deterioration processes drew attention to the particularity of this find. The recognizing and identification of a sporadic gold glass lingua was also the success of the author’s doctoral research. Its appearance is very similar to the medieval ones detected in Venice and in the Middle East. The artists of the turn of the 20th century re-discovered the mosaic technique and the role of gold in their mural compositions. The nature of the Art Nouveau movement favoured the spreading of technology. The overseas Louis Comfort Tiffany became the famous craftsman of this period, in Venice the Liberty-style mosaics are connected to the work of the Salviati-family. In the creation of mosaics inspired by the Hungarian Art Nouveau, the name of Miksa Róth (glass-painter and mosaic artist) is to emphasize. The most significant difference in this period is precisely in the technology, which has a significant impact on the nature and the preparation method of the larger gold surfaces. Contemporary glass art also uses the gold and glass co-effects available. Brigitta Mária Kürtösi Painting and mosaic conservator DLA Translated by: Brigitta Mária Kürtösi Éva Mester Protective window bars, wire nettings and protective glasses - the possibilities of the protection of decorative glazing The vulnerable decorative glass windows are exposed to several harmful chemical and physical impacts. Besides the weather and the vandalism the permanently increasing air pollution causes serious problem as well. In winter the frost cycles, sometimes even more than one per day, are very destroying. When the rainwater accumulated at the junctions of the thin lead canes and the glass plates it has got increases in volume while frosting and volume reduction when it thaws. The harmful effects of the frost, the solar radiation and the driving rain are stronger if they reach directly the windows. Vandalism including wars has been responsible for the complete annihilation of numerous stained glass windows and decorative glazing. Recently the air pollutants, the dust and the chemical compounds may cause the most imminent danger. The protection of the windows has been attempted since the last centuries already. The window bars with various shapes and decoration are parts of the facade elements of the buildings and they can prevent breaking in, but they cannot protect against throwing stones, gun shots and birds. The wire nettings are more efficient but although it gives protection against nesting birds, the gap between the glass plate and the wire nettings is an excellent hiding place for the insects and spiders; and the fallen leaves, the dust and other contaminants cannot be removed from there. The use of protective glasses can be effective solution but not all of them are equally good. They have to be connected to the outer walling; otherwise the wind storms could damage them. Wired glasses have been chosen for a long time but they were not perfect either. The multi-layered, glued, safety glasses, occasionally with bullet proof foil can protect with sufficient safety. In this case the air should be circulated continuously in the gap between the two glass panels to prevent condensation. From an aesthetic point of view the contour of the window bars may interfere with the artistic composition of the glass windows, especially in the sun. The dark shadow of the rustic braid of the wire nettings changes the colour harmony. The square grid of the wired glasses results a lattice pattem on the light surfaces. All these problems can be avoided with the professionally chosen and built in protective glazing, which meets the requirements of thermal engineering and air conditioning. The protection of the decorative glasses fixed in ornamental stone openwork belongs to a separate task group. In those cases it is not always possible to apply the framed protective glazing in front of the decorative glasses. Here the use of the sandwich panels can be expedient. Eva Mester Glas designer DLA, restorer Translated by: Márta Kissné Bendefy 180
