@birbigs
I shouldn't say bad stuff about illiterate people.
I should write it.
http://on.cc.com/16GHqVB
William Du Bois DuddellBorn 1 Jul 1872; died 4 Nov 1917 at age 45.English electrical engineer who invented the sensitive moving coil oscillograph able to photographically record a light spot tracing the oscillations of an electrical voltage, and other electrical instruments. He devised what may be regarded as the first electric musical instrument, the Singing Arc (1899), based on the sounds emitted by an electric carbon arc lamp when its supply voltage was varied. It was an outcome of his investigation to solve the problem of the undesirable humming or whining noises generated by carbon arc street lighting. This research discovered an associated principle of negative resistance. The audio frequencies were generated by switching suitable resonant circuits to the arc. Duddell died aged only 45 years old.« |
