A New Computer-Based Method for Digital Reconstruction of Archeological Bells from the Fragments of Their Casting Mantle

The shape and tuning of bells provide helpful information about where the instrument was manufactured or located and the casting and tuning processes used. For this purpose, both shapes catalogues and methodologies for physical modelling and simulations of musical instruments’ dynamical behaviour are presented in the literature. In several areas of the world, medieval or Renaissance bells are rare because of the remelting of the vast majority of specimens following fractures or breaks caused by wear and tear or traumatic events, such as earthquakes. As a result, the original geometric shape can only be reconstructed by analysing the relevant melting pots excavated by archaeological campaigns. Traditionally, such an analysis is carried out manually by archaeologists. The results are blurred by the difficulty in determining the axis of symmetry and the profiles of small fragments; furthermore, the fragments can rarely be reassembled on the fracture surfaces. To address these drawbacks, this research suggests a computer-based method for virtually reconstructing the bell shape from mantle fragments. Based on a specifically designed geometric-differential analysis of the discrete models of the pieces acquired with a 3D scanner, the approach aims to rebuild the bell’s three-dimensional shape from the definition of its two-dimensional profile.