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Koch & Co. Protractor

American History Museum

Koch & Co. protractor
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  • Koch & Co. protractor
  • Koch & Co. protractor
  • Koch & Co. protractor
  • Koch & Co. protractor

    Object Details

    maker

    Koch & Co.

    Description

    This device for measuring angles bears some resemblance to a combination of a sector and dividers. Two steel arms are screwed together so that one arm may be squeezed and the tops of the arms may pinch an object. The stationary arm is split so that the tension on the arms may be adjusted at the screw. The stationary arm is fastened to a brass piece that is divided by single degrees and marked by tens from 0° to 100°. When the other arm is squeezed, it points to a measurement on the brass piece.
    An owner's signature on the back of the brass piece appears to read, in script, "bgulp." The letters may be Cyrillic or German. A maker's mark is stamped on the back of the stationary arm: KOCH & Co. The firm to which this maker's mark refers is not known. The Department of Entomology in the National Museum of Natural History acquired this object in the late 19th century for use in research. The object is rusted and tarnished.

    Location

    Currently not on view

    Credit Line

    Transfer from National Museum of Natural History

    date made

    before 1900

    ID Number

    1990.0099.05

    accession number

    1990.0099

    catalog number

    1990.0099.05

    Object Name

    protractor

    Physical Description

    brass (overall material)
    steel (overall material)

    Measurements

    overall: .4 cm x 15 cm x 9 cm; 5/32 in x 5 29/32 in x 3 17/32 in

    See more items in

    Medicine and Science: Mathematics
    Science & Mathematics
    Protractors

    Data Source

    National Museum of American History

    Subject

    Mathematics
    Protractor
    Entomology

    Metadata Usage

    CC0

    Link to Original Record

    https://n2t.net/ark:/65665/ng49ca746a7-4a65-704b-e053-15f76fa0b4fa

    Record ID

    nmah_904385

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