A device from the early 20th century to turn sound waves into drawings – creating some of the first waveform illustrations. Those are something anyone who’s ever done any digital recording is familiar with; even the icon for the Voice Memo app on an iPhone is shaped like a waveform.
Herbert Grove Dorsey was one of the University of Florida’s most noted professors (he taught elsewhere, too – some place called Cornell), then became the principal engineer of the United States Coast and Geodetic Survey Radiosonic Laboratory. He’s remembered as being the inventor of the fathometer, a sonic device ships use to measure water depth without stopping. But that creation came in the wake of a whole ream of other, earlier inventions, including (from Wikipedia):
…an automatic deposit box, 1908; an electric indicating system for railways, 1908; a telephone circuit, 1912; a telephone apparatus improvement, 1912; a device for graphically reproducing sound waves, 1912; a submarine mine, 1916; an electrical credit system, 1916; a safety device for electrical circuits, 1916; a submarine control system, 1918; a telegraphy device, 1921; and an auto chain applicator, 1921.