Large sparking magnet on the Nobili pattern. The compound permanent magnet is held together by a brass bracket and fits into a deep slit in the wooden base. The purpose of the second brass bracket with collar attached to the top of the magnet is unclear. When the circuit consisting of the magnet and the contact strip is broken, or quickly restored by a rapid to-and-fro movement of the bobbin, a tiny electric spark is produced between the contact strip and the magnet. It is generated by the induced current due to the opening and closing of the circuit. A small brass plaque is engraved with the words: "Sotto gli auspicii di Leopoldo II. Diede la prima scintilla. Il 30. Gennaio 1832. A.L. Nobili & V. Antinori" ["Under the auspices of Leopold II. Produced the first spark. The 30th… January 1832. A.L. Nobili & V. Antinori"]. A nearly identical instrument with the same plaque is in the Museo Civico of Reggio Emilia. Provenance: Lorraine collections.