From Telegraph to Telephone
Bell’s fantastic invention of the telephone came as a result of his previous endeavors to improve the telegraph. Just like the telephone, the telegraph is a wire-based electrical system. It was also used as a means of communication, but it was limited to receiving and sending one message at a time.
Bell wanted to make it possible to send multiple messages with the telegraph at a time. People have talked about the idea of multiple telegraphs, but no one had been able to come up with anything tangible—until Bell. Bells telegraph was based on the fact that several sound signals could be sent simultaneously if the signals had different pitches.