eidograph|ˈaɪdəgrɑːf, -æ-| [f.Gr. εἶδο-ς form + γράϕειν to sketch.] (See quot.) 1801Hutton Course Math. (1828) II. 81 Professor Wallace's eidograph may be advantageously employed.1869Eng.Mech. 3 Dec. 288/1 The eidograph is a correct instrument for enlarging or reducing drawings.