THE RADIO.- With a mechanism of radiation and transmission of electromagnetic waves at a distance, that is, transmission of electrical signals without cables through which 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 designed by Branly and Odge. In 1895 he was able to send electromagnetic signals at a distance of 1.5 km