TELECOMMUNICATIONS SYSTEMS BASED ON SOUND, WRITING OR LIGHT (IN DIRECT VISION)
The first telegraph to be built, with the scheme of 24 cables per letter of the alphabet, was made by George-Louis LE SAGE (1724-1803). The “Leyden bottle” was used to generate electrical impulses, invented in that city by the Dutchman Pieter Van MUSSCHENBROEK in 1746 (a water bottle with a metal rod fixed in the cap, which, when brought close to an electric machine with his own hand, what it manages to do is act as a condenser plate, while the inner water acted as another, so that it accumulated positive electricity on the inside wall of the bottle and negative electricity on the outside in contact with the hand, receiving a powerful electric shock). The Leyden jar turned out to be a powerful capacitor of electricity due to sudden and not gradual discharges. “Energy condensation is the principle of today’s batteries and capacitors.