Category:Phonautograph

Pho*nau"to*graph, n. Etym: [phono- + gr. -graph.] (physics)

Defn: an instrument by means of which a sound can be made to produce A visible trace or record of itself. It consists essentially of a Resonant vessel, usually of paraboloidal form, closed at one end by a Flexible membrane. A stylus attached to some point of the membrane Records the movements of the latter, as it vibrates, upon a moving Cylinder or plate.