Wichmann 1192 Compensating Polar Planimeter
date: label: date made
content: ca 1930
name: label: maker
content: Gebr. Wichmann
notes: label: Description
content: This German silver and bronzed brass instrument has an 8" fixed-length pole arm with attached cylindrical weight. The arm is marked in script: Wichmann. An adjustable 9-1/2" tracer arm has a support for the tracer point and is evenly divided by tenths numbered from 5 to 36. The interval for each whole number is 5 mm long. A carriage on the tracer arm has a vernier for the scale on the tracer arm and white plastic measuring wheel, vernier, and registering dial. The carriage is marked with a serial number: 17728. A rectangular German silver test plate is marked for 2, 4, and 6 cm.
label: Description
content: A wooden case is covered with black leather and lined with green felt. The top of the case is marked: 1192 Gebr. Wichmann. A loose screw is inside the case. Gebrüder Wichmann (Wichmann Brothers) has sold scientific instruments and office equipment in Berlin since 1873. According to Joachim Fischer, planimeters sold by Wichmann before the 1920s were made by Coradi. Around that time, Wichmann purchased the company founded by Robert Reiss, which thenceforth supplied many of the planimeters sold by Wichmann. It is likely that this example is a Coradi instrument. For a slide rule sold by Wichmann, see MA.293320.2820.
label: Description
content: The instrument was received at the Smithsonian in 1986.
label: Description
content: References: Joachim Fischer to Peggy A. Kidwell, October 19, 1992, Mathematics Collection files, National Museum of American History; A. Brachner, "German Nineteenth-Century Scientific Instrument Makers," in <i>Nineteenth-Century Scientific Instruments and Their Makers</i>, ed. P. R. de Clercq (Amsterdam: Rodopi B. V., 1985), 152; G. Coradi, <i>Catalog d'orientation, No. 37</i> (Zurich, n.d.), 3, in accession file 2011.0043.
label: Location
content: Currently not on view
place: label: place made
content: Germany
topic: label: Subject
content: Mathematics
label: Subject
content: Engineering
setName: label: See more items in
content: Medicine and Science: Mathematics
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content: Planimeters
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content: Science & Mathematics
creditLine: label: Credit Line
content: Gift of Ursula N. Forbes
dataSource: label: Data Source
content: National Museum of American History
identifier: label: ID Number
content: 1986.0316.06
label: catalog number
content: 1986.0316.06
label: accession number
content: 1986.0316
objectType: label: Object Name
content: planimeter
physicalDescription: label: Physical Description
content: german silver (overall material)
label: Physical Description
content: brass (overall material)
label: Physical Description
content: plastic (overall material)
label: Physical Description
content: wood (overall material)
label: Physical Description
content: leather (overall material)
label: Physical Description
content: fabric (overall material)
label: Measurements
content: overall: 26 cm x 9.6 cm x 4.5 cm; 10 1/4 in x 3 25/32 in x 1 25/32 in