Achaeometrical Research in Hungary II., 1988

ANALYSES - METALS - László GERE - László KÖLTŐ: Application of X-ray emission analysis in late medieval and early modern age archaeology

László GERE* - László KÖLTŐ APPLICATION OF X-RAY EMISSION ANALYSIS IN LATE MEDIEVAL AND EARLY MODERN AGE ARCHAEOLOGY A hundred and fifteen copper and bronze fragments have been found within the rich find material unearthed during the excavations of Filipo Scolari's castle at Ozora built between 1416 and 1426. Although the majority of the bronze and copper objects are well preserved, it is often difficult to identify their ages and functions. A new method was tested for the grouping and dating of smaller and larger copper and bronze fragments. This method has not yet been applied in early modern age archaeology, although X-ray emission analysis is familiar to researchers of Avar Period in Hungary. The analysis of copper and bronze finds was carried out between 1992 and 1994 with an Nz-856 analyser developed in the Nuclear Research Institute of the Academy of Sciences in Kaposvár. An aluminium collimator of 2 mm diameter was used. The measuring time varied between 300 to 600 sec. depending on the activity of the J

125 isotope. Altogether, 156 measurements were made (Table 1). The composition of an object in itself is, naturally, of no dating value. The compositions of objects from various periods can be very similar. The analysis of the composition may reveal relations between non-fitting pieces of an object. Similarly, objects with identical or highly similar compositions, presuming that they originate from the same period, may point to workshop centres. The location of such manufacturing centres in space and time facilitates the dating of the object itself, since it is probable that non-ferrous metal working (bronze-casting) developed gradually, even if slowly, in early medieval times. All these involve that accepted methods of research in art history and archaeology cannot be neglected. The reconstruction and dating of a gothic chandelier provides a good illustration for the essence of this method. As a result of the computerised classification of the composition of objects, a few fragments did not fit within either of the groups constituted from functional and chronological aspects. These pieces could be reconstructed as elements of a gothic chandelier. The present paper will deal in detail, with the definition of lighting utensils and gives a short summary of the results derived from the analysis of the entire find material. Gothic chandelier - Group 1.

1-6. (Plate 1.1-6., Fig.l) Stratigraphie analysis revealed that finds 1, 3 and 2 were buried at the end of the 15th, and during the first decades of the 16th с Fragments 5 and 4 must have been buried at the beginning of the Turkish occupation. The chandelier fragments can be characterised by a relatively low copper content (69-78 %) and an unusually high content of zinc (23%), tin and lead. Candle-ring 3 and candle-holder 1 showed nearly identical compositions, they were probably made in the same workshop and in the same period. The minor discrepancy may be due to the fact that they were not cast together, from the same molten metal. Candle holder 2 was not analysed, but its size and shape are totally identical to those of the candle-holder (length: 4.8 cm, diameter: 2.6 cm.), so it certainly belongs to the same group. * State Conservation Centre for Monuments, H-J 036 Budapest, Dugovics T. tér 13-17. ** Directorate of Museums of County Somogy, H-7400 Kaposvár, Fő и. 10. 141