Parallel Rules

Parallel rules help draftsmen, surveyors, cartographers, architects, and navigators draw accurate parallel lines. The instrument comes in two main forms: two rectangular straight edges connected by brass or silver hinges, or a single frame surrounding a roller. The first type was known in Europe by 1600, while Englishman A. George Eckhardt is credited with inventing the second in 1771. The parallel rule was superseded for most uses by the T-square in the 19th century, but navigators continue to use parallel rules in conjunction with gridded charts.

The mathematics collections contain about twenty parallel rules and combination instruments, dating from the late 18th century to the late 20th century and ranging in length from 6 to 24 inches. The objects are made from ebony and other woods, brass, German silver, and plastic. They were manufactured in the United States, England, Italy, and Taiwan. They were used for military surveying, in navigation, in business, in art and technical drawing, and for placing handles on caskets. Several of the objects in this group illustrate innovations added to the basic instrument.

Acknowledgement

The digitization of this group of artifacts was made possible through the generous support of Edward and Diane Straker.

This 21" German silver hinged parallel rule has two small knobs for positioning the instrument. Brass pins secure the hinges. The top blade is marked: U. S. C. & G. S. NO. 323. A fleur-de-lis or letter H appears above the mark.
Description
This 21" German silver hinged parallel rule has two small knobs for positioning the instrument. Brass pins secure the hinges. The top blade is marked: U. S. C. & G. S. NO. 323. A fleur-de-lis or letter H appears above the mark. The edges of the top blade are marked as a rectangular protractor, and the edges of the bottom blade are marked for nautical compass points.
Capt. William Andrew Field (about 1796–1871) of Britain added the protractor and compass scales to hinged parallel rules in 1854. This made it easier for ship navigators to move the rule without losing track of the ship's course. According to the accession file, the U.S. Coast & Geodetic Survey acquired this rule on July 23, 1919, and last issued it on March 18, 1920. Compare to MA.309661 and MA.309662.
References: "Field's Parallel Rule," The Nautical Magazine and Naval Chronicle 23, no. 5 (May 1854): 280; Peggy A. Kidwell, "American Parallel Rules: Invention on the Fringes of Industry," Rittenhouse 10, no. 39 (1996): 90–96; National Maritime Museum, "Captain Field's Improved Parallel Rule," Object ID NAV0602, http://collections.rmg.co.uk/collections/objects/42814.html.
Location
Currently not on view
date made
1919
ID Number
MA.309663
catalog number
309663
accession number
106954
This 21" German silver hinged parallel rule has two small knobs for positioning the instrument. Brass round pieces cover the screws securing the two hinges. An indentation is on both blades at the center of the rule, with a line marking the center.
Description
This 21" German silver hinged parallel rule has two small knobs for positioning the instrument. Brass round pieces cover the screws securing the two hinges. An indentation is on both blades at the center of the rule, with a line marking the center. The edges of the top blade are marked as a rectangular protractor, and the edges of the bottom blade are marked for nautical compass points.
The center of the top blade is marked: U. S. C. & G. S. NO. 331. The right end of the top blade is marked: CAPT. FIELD'S IMPD. The right end of the lower blade is marked: H. HUGHES & SON LTD. LONDON. The left end has the firm's "HUSUN" logo, with a sun above the letters and waves below the letters.
Capt. William Andrew Field (about 1796–1871) of Britain added a protractor and compass scales to hinged parallel rules in 1854. This made it easier for ship navigators to move the rule without losing track of the ship's course. Henry Hughes & Son made marine and aeronautical navigational instruments in London from 1828 to 1947 and incorporated in 1903. According to the accession file, the U.S. Coast & Geodetic Survey acquired this rule on August 21, 1919, and last issued it on September 5, 1922. Compare to MA.309662 and MA.309663.
References: "Field's Parallel Rule," The Nautical Magazine and Naval Chronicle 23, no. 5 (May 1854): 280; Peggy A. Kidwell, "American Parallel Rules: Invention on the Fringes of Industry," Rittenhouse 10, no. 39 (1996): 90–96; National Maritime Museum, "Captain Field's Improved Parallel Rule," Object ID NAV0602, http://collections.rmg.co.uk/collections/objects/42814.html; Science Museum Group, "Henry Hughes and Son Limited," Collections Online – People, http://collectionsonline.nmsi.ac.uk/detail.php?type=related&kv=58792&t=people.
Location
Currently not on view
date made
1919
ID Number
MA.309661
catalog number
309661
accession number
106954
This 21" German silver hinged parallel rule has two knobs for positioning the instrument. Brass round pieces cover the screws securing the two hinges.
Description
This 21" German silver hinged parallel rule has two knobs for positioning the instrument. Brass round pieces cover the screws securing the two hinges. The edges of the top blade are marked as a rectangular protractor, and the edges of the bottom blade are marked for nautical compass points.
The right end of the upper blade is marked: CAPT. FIELD'S IMPD. The center of the lower blade is marked: U. S. C. & G. S. NO. H. 398. The left end has the firm's "HUSUN" logo for the London instrument maker H. Hughes & Son, with a sun above the letters and waves below the letters. A circle around the logo is marked: REGISTERED TRADE MARK (/) GT BRITAIN.
Capt. William Andrew Field (about 1796–1871) of Britain added a protractor and compass scales to hinged parallel rules in 1854. This made it easier for ship navigators to move the rule without losing track of the ship's course. Henry Hughes & Son made marine and aeronautical navigational instruments in London from 1828 to 1947 and incorporated in 1903. According to the accession file, the U.S. Coast & Geodetic Survey acquired this rule on November 6, 1923, and last issued it on February 16, 1924. Compare to MA.309661 and MA.309663.
References: "Field's Parallel Rule," The Nautical Magazine and Naval Chronicle 23, no. 5 (May 1854): 280; Peggy A. Kidwell, "American Parallel Rules: Invention on the Fringes of Industry," Rittenhouse 10, no. 39 (1996): 90–96; National Maritime Museum, "Captain Field's Improved Parallel Rule," Object ID NAV0602, http://collections.rmg.co.uk/collections/objects/42814.html; Science Museum Group, "Henry Hughes and Son Limited," Collections Online – People, http://collectionsonline.nmsi.ac.uk/detail.php?type=related&kv=58792&t=people.
Location
Currently not on view
date made
1923
maker
H. Hughes & Son, Ltd.
ID Number
MA.309662
catalog number
309662
accession number
106954
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.
Description
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 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 started as an agent for a Glasgow instrument workshop which Kelvin had helped establish, sstaying there until about 1918 (after Kelvin's death). He then 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 , http://amhistory.si.edu/navigation/maker.cfm?makerid=43; 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.
White is listed as running his own business on his World War I draft card, dated september 12, 1918. This is available on ancestry.com.
Location
Currently not on view
date made
1932-1950
maker
Kelvin & Wilfrid O. White
ID Number
1984.1002.01
catalog number
1984.1002.01
accession number
1984.1002

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