Capt. Field's Improved Hinged Parallel Rule Signed Kelvin & White Co.

Capt. Field's Improved Hinged Parallel Rule Signed Kelvin & White Co.

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The lower blade of this 24" brass hinged parallel rule is marked: KELVIN – WHITE CO. BOSTON – NEW YORK. The instrument has one rectangular wooden handle and one rectangular black plastic handle. Both handles are attached by crude welding. They may have been added by the previous owner, since Kelvin & White catalog advertisements show round knobs in 1931 and no handles in 1940. The side and top edges of the rule are divided as a rectangular protractor, numbered by tens from 180 to 10 and from 360 to 180. Unlike MA.309661, MA.309662, and MA.309663, the bottom edge is not divided for a protractor or nautical compass points.
Australian shipbuilder Wilfrid O. White (1878–1955) studied in Glasgow, Scotland, with William Thomson, Lord Kelvin (1824–1907), before settling in Boston in 1902. White served as an agent for the Glasgow instrument workshop in which Kelvin held an interest until 1919, when White established the American firm of Kelvin & Wilfrid O. White. The company was renamed Wilfrid O. White & Sons, Inc., in 1950. Throughout its existence the firm charged $28.00 for the 24" brass version of "Captain Field's improved parallel rule," model number 554. The markings in this example are like those shown in the 1940 catalog.
References: Kelvin & Wilfrid O. White Company, 1931 Catalogue of . . . Navigational Instruments and Equipment (Boston, 1931), 37; Kelvin & Wilfrid O. White Company, Catalog No. 40–Y (Boston, 1940), 35; Peggy A. Kidwell, "American Parallel Rules: Invention on the Fringes of Industry," Rittenhouse 10, no. 39 (1996): 90–96; Deborah J. Warner, "Browse by Maker: Kelvin & Wilfrid O. White," National Museum of American History Physical Sciences Collection: Navigation ,; T. N. Clarke, A. D. Morrison-Low, and A. D. Simpson, Brass & Glass: Scientific Instrument Making Workshops in Scotland (Edinburgh: National Museums of Scotland, 1989), 252–275.
Currently not on view
Object Name
parallel rule
date made
Kelvin & Wilfrid O. White
place made
United States: Massachusetts, Boston
place distributed
United States: Massachusetts, Boston
Physical Description
wood (overall material)
plastic (overall material)
brass (overall material)
overall: 3 in x 24 in; 7.62 cm x 60.96 cm
ID Number
catalog number
accession number
Credit Line
Transfer from U.S. Federal Maritime Commission
See more items in
Medicine and Science: Mathematics
Measuring & Mapping
Science & Mathematics
Parallel Rules
Data Source
National Museum of American History

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