For the secure horizontal fitting of adjacent stone blocks, brass or iron “clamps” in the form of I were usually used, which were placed in corresponding carved sockets in the blocks and were stabilised and protected with lead casting. For their stable vertical mounting, “dowels” were used, i.e. brass or iron laminas that were placed in a similar manner. For the secure connection of the column drums, the “empolia” (i.e. wooden elements of square cross-section that were placed in corresponding square notches in the centre of the drums) were used. The “empolia” had holes in their centre and were linked together by the “pole”, a usually wooden vertical pin, allowing the free rotation of the drums.