TELECOMMUNICATIONS SYSTEMS BASED ON SOUND, WRITING OR LIGHT (IN DIRECT VISION)
The first telegraph to be built, following the scheme of 24 cables per letter of the alphabet, was made by George-Louis LE SAGE (1724-1803), based on the “Leyden bottle”, created by the Dutchman Pieter Van MUSSCHENBROEK in 1746, was a water bottle with a metal rod fixed to the cap, which, when brought close to an electrified conductor, forms a capacitor/capacitor, that is, it stores energy. In the Leyden jar, the positive charge is on the inside and the negative charge is on the outside. This principle was the basis for electric cells and batteries.