Instrument used by artists, draughtsmen and technical designers to copy an original drawing, diagram or plan on the same, or on an enlarged or reduced scale; it is sometimes erroneously referred to in commercial and technical use as a pentagraph. The pantograph is made of rods and pins in the form of a parallelogram (the name by which it was first known in the 17th century) and uses the same principle as that found in the geometric figure: that it can easily change its configuration but will always remain a parallelogram. This can perhaps be visualized and understood best by picturing a collapsible gate such as those found at level-crossings. On the artist’s pantograph, one corner is fixed, and a pencil or tracing-point is added to the corner diagonally opposite. If a free point is then manipulated over the outlines of the subject to be copied, the pencil or tracing-point duplicates its movements and so produces the copy. The pantograph is supported on castors, and the joints of the rods are very loose, so it moves extremely easily but can be difficult to control. An eidograph is a more complicated, but more stable, version.

• pantographs
  • England, §VII, 4: Ceramics, 1831–1900
  • Photosculpture
  • Typography, §2: 19th-century technology