Motograph \Mo"to*graph\, n. [L. movere, motum, to move +
-graph.] (Elec.)
A device utilized in the making of a loud-speaking telephone,
depending on the fact that the friction between a metallic
point and a moving cylinder of moistened chalk, or a moving
slip of paper, on which it rests is diminished by the passage
of a current between the point and the moving surface.
[obsolescent] -- {Mo`to*graph"ic}, a.
[Webster 1913 Suppl.]