Optigraph

Op´ti`graph

n.

1.

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.

Webster's Revised Unabridged Dictionary, published 1913 by G. & C. Merriam Co.