Webster's Revised Unabridged Dictionary · 1913

Optigraph

Optigraph , noun

[Optic + -graph: compare French opticographe. See Optic, a. ]

A telescope with a diagonal eyepiece, suspended vertically in gimbals by the object end beneath a fixed diagonal plane mirror. It is used for delineating landscapes, by means of a pencil at the eye end which leaves the delineation on paper.