Gavard Perspectograph or Diagraph

The perspectograph (also called a diagraph) was used to make enlarged or reduced two-dimensional drawings of three-dimensional objects. This example consists of a metal bar at the base, with an ivory plate which holds a pencil with weight cup. A hollow brass tube on a wheel and pivot fits into this base with screws. A mark on the connection for this tube reads: GAVARD. An eyepiece would be attached to the tube, but the linkage is missing. The assembled tube and bar rolls along a metal guide piece which has prickers to secure it to the paper. Another brass tube may attach to a brass slider on the base bar. A rectangular sight would attach to this tube if the necessary parts were there. Both tubes have spools for thread, which is wound around a card in the case. The case also contains two hollow rectangular joiners, two keys on a white ribbon, and a stone weight.
The wooden case has a metal handle, lock, and two hooks. The braces in the case are lined with felt.
Adrien Gavard made the first perspectograph on a design patented in England by Jean-Marie Etienne Ardit in 1831, and in France by Gavard himself in 1834. He manufactured perspectographs and pantographs which were sold in the United States, and was in business until about 1900.
A pamphlet entitled "Rules for Using the Diagraph" was received with the object. It is for a different instrument, but handwritten hints in the back relate to the "French Diagraph." The pamphlet is catalogued as 1987.0923.03.
Howard Dawes, "Scientific Instruments in Perspective," Bulletin of the Scientific Instrument Society, no. 17 (1988): pp. 4-6.
Deborah J. Warner, "French Instruments in the United States," Rittenhouse, 8, (1993): p. 23.
Susan C. Piedmont-Palladino, ed., Tools of the Imagination: Drawing Tools and Technologies from the Eighteenth Century to the Present, New York: Princeton Architectural Press, 2007, p. 67. this is an illustration of a complete version of the apparatus.
Currently not on view
date made
Gavard, Adrien
place made
France: Île-de-France, Paris
Physical Description
metal (overall material)
brass (overall material)
wood (overall material)
overall: 10.6 cm x 72.3 cm x 10.6 cm; 4 3/16 in x 28 15/32 in x 4 3/16 in
ID Number
accession number
catalog number
Credit Line
Gift of Worcester Polytechnic Institute
Drafting, Engineering
See more items in
Medicine and Science: Mathematics
Science & Mathematics
Single Drawing Instruments
Data Source
National Museum of American History


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