Complex sentence: Guglielmo Marconi was one of the first people to believe that radio waves might be used to transmit information long distance by telegraphy, using Morse code; he developed the first practical radiotelegraphy transmitters and receivers.
Split into simpler sentences: Guglielmo Marconi was one of the first people to believe that radio waves might be used to transmit information long distance by telegraphy, using Morse code. He developed the first practical radiotelegraphy transmitters and receivers.