Wichmann 1192 Compensating Polar Planimeter

Object Details

Gebr. Wichmann

Description

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.

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.

The instrument was received at the Smithsonian in 1986.

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 Nineteenth-Century Scientific Instruments and Their Makers, ed. P. R. de Clercq (Amsterdam: Rodopi B. V., 1985), 152; G. Coradi, Catalog d'orientation, No. 37 (Zurich, n.d.), 3, in accession file 2011.0043.

Location

Currently not on view

Credit Line

Gift of Ursula N. Forbes

ca 1930

ID Number

1986.0316.06

catalog number

1986.0316.06

accession number

1986.0316

Object Name

planimeter

Physical Description

german silver (overall material)

brass (overall material)

plastic (overall material)

wood (overall material)

leather (overall material)

fabric (overall material)

Measurements

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

place made

Germany

See more items in

Medicine and Science: Mathematics

Planimeters

Science & Mathematics

National Museum of American History

subject

Mathematics

Engineering

Record ID

nmah_1215080

Metadata Usage (text)

CC0

GUID (Link to Original Record)

http://n2t.net/ark:/65665/ng49ca746aa-bbda-704b-e053-15f76fa0b4fa