MCI places order for 90,000 miles of fiber optic cable. Thomas Edison invents the phonograph. Emile Berliner invents gramophone disks. Valdemar Poulsen discovers that sound changes magnetic pattern in wires. Poulsen invents telegraphone.
German firms develop magnetic tape for sound recordings.
Tape recorder sold in the United States. 1948 Long-playing records introduced. Phillips develops audiotape cassettes. Peter Mark Roget proposes theory of persistent vision. 1872 Eadweard Maybridge does photographic studies of animals in motion.