Abstract
One of the main issues still not resolved is to what extent casters were capable to change the composition of the bronze objects in order to meet the demands of the “market”. To face this problem it is necessary to study a large number of items produced by a single foundry with modern analytical techniques. The discovery of a Dolium at the end of 1800, buried near a furnace containing more than 14,000 pieces of bronze objects allowed performing compositional analysis on virtually every item of daily use. The objects were found in central Italy near Bologna in the so called “ripostiglio di San Francesco” (“hoard of San Francesco”). 431 measurements were carried out using portable energy dispersive x-ray fluorescence analysis (EDXRF). Abundance of the main elements (Cu, Sn, Pb, Fe, Sb, Ag, As) in the bronze alloy was analysed on 229 objects, after their brushing in order to remove the “patina” of oxidation. On 126 objects a single point was analysed (with measurement repetition), while on 155 objects two or more points were investigated. The research objects were chosen among the 14,000 pieces by museum curators and were grouped in 15 categories based on a visual and functional study. The complete data set was studied by chemometric analyses with Explorative Data Analysis techniques. The results of this preliminary study could not identify a clear correlation between composition and destination of use. However, some of the technical aspects of the fusion process were highlighted by this research.
Keywords: Ancient bronze, Alloy composition, Chemometry, Casters technique, Bronze use
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