• Webster's Revised Unabridged Dictionary
    • n Optigraph 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.
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Century Dictionary and Cyclopedia
    • n optigraph A form of telescope constructed for the purpose of copying landscapes, etc. It is suspended vertically in gimbals by the object-end, beneath a fixed diagonal plane mirror, which reflects the rays from the objects to be drawn through the object-glass of the instrument to a speculum, and thence through the eye-glass to the eye. Between the eye and the speculum is a piece of parallel-faced glass with a small dot on its center, exactly in the focus of the eyeglass. This dot is made to pass over the outlines of an object, and a pencil fixed at the eye-end traces the delineation on paper.
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Webster's Revised Unabridged Dictionary
Optic, + -graph,: cf. F. opticographe,. See Optic (a.)