Troughton and Simms Dividing Engine


This engine produced finely graduated circular scales such as those used on surveying instruments called theodolites. It was ordered by the U.S. Coast Survey from the London instrument maker Edward Troughton in 1832, completed by the successor firm of Troughton and Simms after Troughton’s death, and delivered to the Coast Survey in 1842. Over its time there, it was modified by Joseph Saxton and later George N. Saegmuller. The dividing engine was transferred from the Coast and Geodetic Survey to the Smithsonian in 1929.

The instrument has a brass circle four feet across on heavy cone center bearings, supported by a 4 ½ foot iron circle. The cone bearing socket is mounted on a heavy fixed tripod two feet high. The instrument is signed: Troughton & Simms, London, 1841.

The instrument is presently (2019) unavailable for study or exhibition.


Accession file 106350.

Chris Evans, “Precision Engineering: and Evolutionary Perspective,”, MSc Thesis, Cranfield Institute of Technology, 1987, pp. 77-78.

F.B. Hassler, A Report from the Superintendent of the Coast Survey and of the Fabrication of Standard Weights and Measures, Senate Report 11, 27th Congress, 3rd Session, December 20, 1842, p. 4.

Joseph Henry, “Memoir of Joseph Saxton,” Biographical Memoirs of the National Academy of Sciences, vol. 1, pp. 311-312.

Date Made: 1841Date Made: ca 1841

Maker: Troughton and Simms

Place Made: United Kingdom: England, London

Subject: Ruling and Dividing EnginesMathematics


See more items in: Medicine and Science: Mathematics


Exhibition Location:

Credit Line: Transfer from U.S. Coast and Geodetic Survery

Data Source: National Museum of American History

Id Number: MA.309643Accession Number: 106350Catalog Number: 309643

Object Name: Dividing Engine


Record Id: nmah_1302754

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