Circular Dividing Engine for Optical Instruments
date: label: date made
content: ca 1900-1950
notes: label: Description
content: By the first half of the twentieth century, American manufacturers of drawing instruments made special purpose dividing engines, instruments in which the division of scales was controlled automatically by advance of a screw. This compact metal instrument is such a device. According to the donor, it was given to him by an employee of instrument manufacturer Keuffel & Esser Company. It was specifically used to make scales on transparent materials involved in measurement and aiming. It also helped locate crosshairs on such instruments.
label: Description
content: The object is largely made of brass, with parts of steel, copper, and aluminum. A divided circle on the left side has a scale running from 0 to 99, divided to units. It is set to control the rotation of the screw that runs across the base and governs the rotation of the piece above that is being divided. The object has no other maker’s marks.
label: Description
content: Reference:
label: Description
content: Accession file 250506.
label: Location
content: Currently not on view
topic: label: Subject
content: Ruling and Dividing Engines
label: Subject
content: Mathematics
setName: label: See more items in
content: Medicine and Science: Mathematics
creditLine: label: Credit Line
content: Gift of L. C. Eichner
dataSource: label: Data Source
content: National Museum of American History
identifier: label: ID Number
content: MA.322757
label: catalog number
content: 322757
label: accession number
content: 250506
objectType: label: Object Name
content: dividing engine
physicalDescription: label: Physical Description
content: metal (overall material)
label: Measurements
content: overall: 16.6 cm x 13.5 cm x 11 cm; 6 17/32 in x 5 5/16 in x 4 11/32 in