Gavard Perspectograph or Diagraph
date: label: date made
content: 1850-1900
name: label: maker
content: Gavard, Adrien
notes: label: Description
content: 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.
label: Description
content: The wooden case has a metal handle, lock, and two hooks. The braces in the case are lined with felt.
label: Description
content: J.D.C. Gavard made the first perspectograph on a design patented in England for him Jean-Marie Etienne Ardit in 1831, and in France by Gavard himself in 1834. His business, which passed to Adrien Gavard, manufactured perspectographs and pantographs which were sold in the United States, and was active until about 1900.
label: Description
content: 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.
label: Description
content: References:
label: Description
content: Howard Dawes, "Scientific Instruments in Perspective," <I>Bulletin of the Scientific Instrument Society</I>, no. 17 (1988): pp. 4-6.
label: Description
content: Deborah J. Warner, "French Instruments in the United States," <I>Rittenhouse</I>, 8, (1993): p. 23.
label: Description
content: Susan C. Piedmont-Palladino, ed., <I>Tools of the Imagination: Drawing Tools and Technologies from the Eighteenth Century to the Present</I>, New York: Princeton Architectural Press, 2007, p. 67. this is an illustration of a complete version of the apparatus.
label: Description
content: Comments by David Bryden at the collections web page of the National Museum of American History.
label: Location
content: Currently not on view
place: label: place made
content: France: Île-de-France, Paris
topic: label: Subject
content: Mathematics
label: Subject
content: Drafting, Engineering
setName: label: See more items in
content: Medicine and Science: Mathematics
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content: Single Drawing Instruments
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content: Science & Mathematics
creditLine: label: Credit Line
content: Gift of Worcester Polytechnic Institute
dataSource: label: Data Source
content: National Museum of American History
identifier: label: ID Number
content: 1987.0923.02
label: accession number
content: 1987.0923
label: catalog number
content: 1987.0923.02
objectType: label: Object Name
content: drawing instrument
physicalDescription: label: Physical Description
content: metal (overall material)
label: Physical Description
content: brass (overall material)
label: Physical Description
content: wood (overall material)
label: Measurements
content: 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