Warner & Swasey Circular Dividing Engine

Warner & Swasey Circular Dividing Engine

Usage conditions apply
Dividing engines scribed the fine scales traced along the edges of mathematical, navigational, and astronomical instruments. From the time of Englishman Jesse Ramsden in the late eighteenth century, free-standing dividing engines with the advance or the tracer driven by a carefully controlled screw were used by scientific instrument makers (for an example of Ramden's dividing engine, see MA.215518).
In 1893, the U.S. Naval Observatory ordered a new meridian circle from the Cleveland firm of Warner &Swasey. The instrument required metal circles, 26 1/2" inches diameter, divided to two minutes of arc (10,800 divisions). To create scales of sufficient precision, Ambrose Swasey designed this circular dividing engine. It would be used at Warner & Swasey at least into the 1950s, and was given to the Smithsonian in 1974 along with documentation (see record MA.313774.02 and MA.313774.03) and a box of parts (MA> 313774.22)
Accession file 313774.
C. Evans,Precision Engineering: An Evolutionary View, Bedford: Cranfield, 1987.
Currently not on view
Object Name
dividing engine
date made
Warner & Swasey Company
place made
United States: Ohio, Cleveland
overall: 64 in x 54 in x 54 in; 162.56 cm x 137.16 cm x 137.16 cm
ID Number
catalog number
accession number
Credit Line
Gift of Warner & Swasey Company
Ruling and Dividing Engines
See more items in
Medicine and Science: Mathematics
Data Source
National Museum of American History
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