Baudot: The Five-Key Code That Raced Morse Henry's magnets and relays made long lines possible, and he gave the knowledge away. This guide covers his telegraph work and the credit he declined to patent. Quick facts Classroom line 1831, one mile Magnet record over a ton lifted Relay principle signal refresh Smithsonian first secretary Unit henry (H) When Morse needed to know whether an electromagnet could work a distant lever, Henry had already answered the question in print. His testimony later anchored the Morse patents - the professor's science, wearing the inventor's name. Keep learning - morse code translator with audio playback: Morse Code Works - free Morse code tools and guides. Reference chart