Cast
- Luigi Pavese as Antonio Meucci
- Leda Gloria as Ester, sua moglie
- Nerio Bernardi as Alexander Graham Bell
- Greta Gonda as Consuelo Ispahan
- Osvaldo Valenti as Giovane Giuseppe Garibaldi
- Armando Migliari as Elisha Gray
- Rubi D'Alma as Liliana Montes
- Anna Valpreda as Mary
- Emilio Petacci as Sam Cloton
- Nino Pavese as Onorevole Closter