Three-nail microphone, c 1878.
© Science Museum / Science & Society Picture Library
This simple three-nail microphone was the work of English-born music profesor David Hughes (1831-1900). Hughes discovered that loose electrical contacts are very sensitive to vibrations, including sound. By placing three nails on a wooden board, Hughes created a transducer more efficient than Bell's telephone. This particular model could even detect a fly's footstep. Hughes was so impresed by its ability that he likened it to a 'sound microscope' and decided to call it a 'microphone'. Hughes's microphone was the precursor of the modern carbon microphone.