Opeidoscope

1 definition found

From The Collaborative International Dictionary of English v.0.48 [gcide]:

  Opeidoscope \O*pei"do*scope\, n. [Gr. ?, ?, voice + e'i^dos form
     + -scope.] (Physics)
     An instrument, consisting of a tube having one end open and
     the other end covered with a thin flexible membrance to the
     center of which is attached a small mirror. It is used for
     exhibiting upon a screen, by means of rays reflected from the


     mirror, the vibratory motions caused by sounds produced at
     the open end of the tube, as by speaking or singing into it.
     --A. E. Dolbear.
     [1913 Webster]