Wheatstone, Charles (1802–1875)
Charles Wheatstone was a British physicist and inventor. In 1843, he improved and popularized a device that accurately measures electrical resistance. Widely used in laboratories, it became known as the Wheatstone bridge. By 1837, he had invented an electric telegraph (with the help of Joseph Henry) before Morse. He also invented the stereoscope and the concertina, and coined the the term "microphone" for a sound magnifier.