Tachistoscope
Pronunciation : Ta*chis"to*scope, n. [Gr.
Part of Speech : superl.
Definition : Defn: An apparatus for exposing briefly to view a screen bearing letters or figures. It is used in studying the range of attention, or the power of distinguishing separate objects in a single impression.
of swift + -scope.] (Physiol.)
Source : Webster's Unabridged Dictionary, 1913