E se Marconi........la storia mancata

Guglielmo Marconi used the coherer in his first experiments for detecting electrical discharges from thunderstorms (Livorno 1892-93) and for realizing remote communications (Pontecchio Marconi 1895). The coherer was invented by Temistocle Calzecchi Onesti, as recognized after years and years of disputes. In 1884 his communication to the “Accademia del Cimento” about his device, called cannellino, removes any possibility of misunderstanding. The Calzecchi Onesti’s cannellino is a coherer equipped with a crank, that aimed to restore the insulation conditions after the conduction conditions triggered by the radiofrequency signal. The crank was much more practical and functional than the hammer described by Branly and Lodge and used by Guglielmo Marconi in his experiments. We believe that Marconi did not know the experiments by Calzecchi Onesti. In a previous communication, the authors of this paper illustrated the personality and the work of Temistocle Calzecchi Onesti and described the reconstruction of the cannellino, operated according to the instructions of its inventor. Recent measurements have been carried out on the realized instrument with the aim to highlight the different behaviour of the two systems. These measurements confirm the best performance of the cannellino. We wonder why Marconi did not use the cannellino in his experiments. The authors of this paper formulate some hypotheses and try to figure out the evolution of the electric signal revelation in the case Marconi had known Calzecchi Onesti and his cannellino.