Circular Dividing Engine
notes: label: Description
content: This circular dividing engine fits on a table. It has an iron, T-shaped base with three holes for attaching the engine to a base. A mechanism with lever handle and tracer arm, a microscope on a vertical post, a brass disk, and a screw with handle are attached to the base. An empty screwhole for attaching another mechanism is across from the microscope. The tension of the lever handle can be adjusted with at least seven screws. The lever moves the tracer arm into position for marking; the diamond tip of this arm is missing. The microscope contains its original glass lenses. While they work, they do not let in much light.
label: Description
content: The brass disk is calibrated counterclockwise by minute from 0 to 360. From 55 to 15 degrees, the following marks also appear: 1/30 19..20; 1/40 14..15; 1/40 29..30; 1/60 29..30; 1/60 59..60. A silver metal plunger is at the center of the disk. The plunger rests on two small brass disks which are marked with various unnumbered divisions. When these disks are removed, screwholes which radiate from the center of the large disk in twelve sets of four can be seen. The large disk is turned slowly by means of a screw mechanism on the right side of the disk. This screw has a handle with a plastic or rubber tip, a wheel calibrated from 0 to 90 by degree, three screws for making adjustments, and the screw threads which fit against the large disk. There is no corrector cam. The wheel has been marked by a user at various points of interest: 0, 16, 28, 45, 64, and 81 degrees.
label: Description
content: The engine probably dates to the late nineteenth century. There is no maker’s mark.
label: Description
content: References: Chris Evans, “Precision Engineering: An Evolutionary Perspective,” M.Sc. thesis, Cranfield Institute of Technology, 1987.
label: Description
content: Anthony A. Leiserowitz, “The Dividing Engine in History,” <www.surveyhistory.org/the_dividing_engine.htm> (accessed 4 December 2002).
label: Description
content: University of Vermont Physics Department, “Dividing Engine” <www.uvm.edu/~dahammon/museum/dividingengine.html> (accessed 4 December 2002).
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 Worcester Polytechnic Institute
dataSource: label: Data Source
content: National Museum of American History
identifier: label: ID Number
content: 1987.0923.01
label: catalog number
content: 1987.0923.01
label: accession number
content: 1987.0923
objectType: label: Object Name
content: dividing engine
physicalDescription: label: Physical Description
content: metal (overall material)
label: Measurements
content: overall: 29.8 cm x 51.5 cm x 32 cm; 11 23/32 in x 20 9/32 in x 12 19/32 in