THE RADIO. – With a mechanism of radiation and transmission of electromagnetic waves at a distance, that is, transmission of electrical signals without wires through which the current circulates. Guglielmo Marconi (1874-1937). Aware of Hertz’s findings through his professor in Bologna Augusto RighiI (1850-1920), he built his first transmitter and receiver of Hertzian waves, using instruments previously devised by Branly and odge. In 1895 it was able to send electromagnetic signals at a distance of 1.5 km.