An Original Mid-Nineteenth Century Scientific Instrument in Italy: Vincenzo Vignola’s Induction Coil

It is well known that the induction coil was invented in the mid-1830s, but its most significant improvements were made between the late 1830s and 1851. During these years a lot of research was aimed at improving the functionality and effectiveness of the device. In Italy one of the very first attempts at improvement was made first by an instrument maker from Milan, Carlo Dell’Acqua, and secondly, by a priest from Verona, Vincenzo Vignola. In 1851, Vignola was awarded the gold medal from the Academy of Agriculture, Arts and Commerce of Verona for having introduced important and useful changes to the Callan electromotor. This event opened up the discovery of a number of very interesting, unpublished hand-written documents, as well as the discovery of the device itself, provided with an almost unique self-acting commutator-interrupter system. Today this apparatus is preserved at the Physics Museum “Antonio Maria Traversi” in Venice.