Dividers

A collection of dividers and compasses in the Division of Medicine and Science's Mathematics collection.

These objects include "plain" dividers, which consist of just the legs, and "wing" or "bow" dividers, which have a crosspiece that may be used to adjust the precision of the instrument and fix its width in place. Most of the oldest instruments in the overall group are dividers.

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Wing Dividers

These brass and steel dividers are joined by a ball-shaped hinge. The steel pointed tips of each leg are approximately 3-1/2" long. The brass portions continue for nearly another 9". A brass arc, or wing, with a circumference of approximately 8-1/2", joins the legs.
Description
These brass and steel dividers are joined by a ball-shaped hinge. The steel pointed tips of each leg are approximately 3-1/2" long. The brass portions continue for nearly another 9". A brass arc, or wing, with a circumference of approximately 8-1/2", joins the legs. A butterfly screw allows the arc to be removed. A wing nut tightens the adjustable leg so that the dividers are set in position. On the outsides of the legs, below the two screws, the dividers are stamped with wheels that have six spokes and a small circle at the center. According to a note in the accession file, this mark represents the heraldic symbol of the city of Osnabrück, Germany.
Dividers are alternatively called (non-drawing) compasses, or Zirkel in German. Draftsmen used them to measure distances and to create circles. This pair was probably manufactured in the 18th century.
Reference: Maya Hambly, Drawing Instruments: 1580–1980 (London: Sotheby's Publications, 1988), 69–79.
Location
Currently not on view
date made
1700s
ID Number
MA.322756
accession number
248674
catalog number
322756

Group of Two Dividers

Early modern European draftsmen used dividers to transfer distances from measuring instruments to architectural, topographical, mechanical, and engineering drawings. They also employed dividers in reading off distances on a sector, so that a numerical calculation could be made.
Description
Early modern European draftsmen used dividers to transfer distances from measuring instruments to architectural, topographical, mechanical, and engineering drawings. They also employed dividers in reading off distances on a sector, so that a numerical calculation could be made. The first pair of dividers has metal needle points inserted into brass legs. Decorative horizontal lines are engraved into the brass. The instrument is almost 4" long.
The second pair of dividers is entirely made of brass. Two sets of three horizontal lines are engraved into the outside of the legs. On one leg, a wheel is engraved below the lines. The instrument is 3-1/4" long.
References: J. F. Heather, Mathematical Instruments: Their Construction, Adjustment, Testing, and Use, rev. ed. (London: Crosby Lockwood and Co., 1870), i:13, 42.
Reference:
Sotheby & Company, Catalogue of a Collection of Scientific Instruments, the Property of the Late Henry Russel Wray, London, 1959 (a copy of the catalogue is in the accession file).
Location
Currently not on view
date made
18th century
ID Number
MA.316931
accession number
219305
catalog number
316931

Dod Protractor and Parallel Rule

This brass semicircular protractor is divided by single degrees and marked by tens from 10° to 90° to 10°. It is attached with metal screws to a set of brass parallel rules. Brass S-shaped hinges connect the rules to each other.
Description
This brass semicircular protractor is divided by single degrees and marked by tens from 10° to 90° to 10°. It is attached with metal screws to a set of brass parallel rules. Brass S-shaped hinges connect the rules to each other. The bottom left screw on the parallel rules does not attach to the bottom piece. A rectangular brass arm is screwed to the center of the protractor. A thin brass piece screwed to the arm is marked with a small arrow for pointing to the angle markings. The protractor is stored in a wooden case, which also contains a pair of metal dividers (5-1/4" long).
The base of the protractor is signed: L. Dod, Newark. Lebbeus Dod (1739–1816) manufactured mathematical instruments in New Jersey and is credited with inventing the parallel rule protractor. He served as a captain of artillery during the Revolutionary War and made muskets. His three sons, Stephen (1770–1855), Abner (1772–1847), and Daniel (1778–1823), were also noted instrument and clock makers. The family was most associated with Mendham, N.J. (where a historic marker on N.J. Route 24 indicates Dod's house), but Dod is known to have also lived at various times in Newark.
ID number MA.310890 is a similar protractor and parallel rule. Compare also to a Dod instrument owned by the Metropolitan Museum of Art in New York, http://www.metmuseum.org/Collections/search-the-collections/5535.
References: Bethuel Lewis Dodd and John Robertson Burnet, "Biographical Sketch of Lebbeus Dod," in Genealogies of the Male Descendants of Daniel Dod . . . 1646–1863 (Newark, N.J., 1864), 144–147; Alexander Farnham, "More Information About New Jersey Toolmakers," The Tool Shed, no. 120 (February 2002), http://www.craftsofnj.org/Newjerseytools/Alex%20Farnham%20more%20Jeraey%20Tools/Alex%20Farnham.htm; Deborah J. Warner, “Surveyor's Compass,” National Museum of American History Physical Sciences Collection: Surveying and Geodesy, http://americanhistory.si.edu/collections/surveying/object.cfm?recordnumber=747113; Peggy A. Kidwell, "American Parallel Rules: Invention on the Fringes of Industry," Rittenhouse 10, no. 39 (1996): 90–96.
Location
Currently not on view
date made
late 1700s
maker
Dod, Lebbeus
ID Number
1978.2110.06
accession number
1978.2110
catalog number
336732

Japanese Proportional Dividers

These brass dividers have metal points, short at one end and longer at the other. The legs are slotted to allow a brass set screw to be placed at one of several positions on two proportional scales that are engraved on one of the legs.
Description
These brass dividers have metal points, short at one end and longer at the other. The legs are slotted to allow a brass set screw to be placed at one of several positions on two proportional scales that are engraved on one of the legs. The scales are labeled with Japanese characters, but they are presumably for drawing lines and circles at different ratios.
The Japanese Empire Department of Education displayed this instrument at the 1876 World's Fair, the Centennial Exhibition in Philadelphia, in order to demonstrate its nation's modernity and progress. In fact, the Department of Education had just been established in 1870 to replace an Educational Board and assume a more active role in the management of primary, middle, and secondary schools. John Eaton, the U.S. Commissioner of Education, arranged for the transfer of the entire exhibit in which these dividers appeared to the Bureau of Education (then part of the Department of the Interior) for a planned museum. The museum closed in 1906 due to high maintenance costs, and much of the collection was transferred to the Smithsonian in 1910.
Other educational mathematical objects exhibited by Japan in 1876 include MA.261301, MA.261305, and MA.261306.
References: Michael Scott-Scott, Drawing Instruments (Aylesbury, England: Shire Publications Ltd., 1986), 14–15; Japan. Department of Education, An Outline History of Japanese Education: Prepared for the Philadelphia International Exhibition, 1876 (New York: D. Appleton, 1876), 121–122, 191–202; U.S. Centennial Commission, International Exhibition, 1876. Reports and Awards , ed. Francis A. Walker (Washington, D.C.: Government Printing Office, 1880), viii:143, 335; U.S. Bureau of Education, Annual Report of the Commissioner (1876), ccxi–ccxii.
Location
Currently not on view
date made
before 1876
ID Number
MA.261313
accession number
51116
catalog number
261313

Plain Dividers Retailed by Keuffel & Esser

These plain dividers have grooved brass legs with steel points and are held together with a screw. Two small holes are in the joint on either side of the bottom end of the screw.
Description
These plain dividers have grooved brass legs with steel points and are held together with a screw. Two small holes are in the joint on either side of the bottom end of the screw. The instrument arrived at the Smithsonian in a case (now lost) marked: Keuffel & Esser Co., New York. The dividers are similar to the 4-1/2" plain dividers from Switzerland advertised (without a case) in James Queen's 1883 catalog for $1.50. The instrument slightly resembles 4-1/4" plain dividers from France sold by K&E in the 1880s and 1890s for between 24 and 85 cents. It is not depicted in K&E's 1909 and 1936 catalogs.
References: James W. Queen & Co., Priced and Illustrated Catalogue of Mathematical Instruments (Philadelphia, 1883), 22; Catalogue and Price-List of Keuffel & Esser Co., 23rd ed. (New York, 1892), 62, 102; Trade Price List. An Annex to the General Catalogue (Twenty-Eighth Edition) of Keuffel & Esser Co. (New York, n.d.), 30.
Location
Currently not on view
date made
late 19th century
ID Number
MA.335341
accession number
305958
catalog number
335341

Bow Dividers

This steel and brass instrument is called a bow divider because the nut on the side may be tightened or loosened to hold the instrument at a desired width. This example is similar to one sold by Keuffel & Esser, although the top of the handle is different.
Description
This steel and brass instrument is called a bow divider because the nut on the side may be tightened or loosened to hold the instrument at a desired width. This example is similar to one sold by Keuffel & Esser, although the top of the handle is different. There is no maker's mark.
Reference: Catalogue of Keuffel & Esser Co. , 33rd ed. (New York, 1909), 62.
Location
Currently not on view
date made
ca 1900
ID Number
1978.2110.12
accession number
1978.2110
catalog number
336738

Plain Dividers by Société des Lunetiers

This brass instrument has steel points that are both bent at the end. It has a ridged cylindrical handle and is held together with a screw. One arm opens and closes at the joint.
Description
This brass instrument has steel points that are both bent at the end. It has a ridged cylindrical handle and is held together with a screw. One arm opens and closes at the joint. That arm is marked: STE DES LUNETIERS (/) FRANCE.
In 1849 several workshops in Paris formed the Société des Lunetiers to cooperatively sell spectacles and mathematical instruments. Since 1972, the company has been known as Essilor.
Keuffel & Esser, an American maker and dealer of slide rules and drawing instruments, donated this object to the Smithsonian in 1971. Part of a paper tag received with the object has been lost, but the remaining portion suggests these dividers may have been used by company employees preparing lettering. None of the dividers offered in K&E catalogs in 1909, 1921, or 1936 resemble this instrument.
References: Nicolàs de Hilster, "Société des Lunetiers," Geodetic Instruments, http://www.dehilster.info/index.php?doc=http://www.dehilster.info/instrumenten/theodolite1/sdl.html; "About Essilor," http://www.essilor.co.nz/about_essilor/.
Location
Currently not on view
date made
ca 1900
maker
Société des Lunetiers
ID Number
MA.335260
accession number
306012
catalog number
335260

Plain Dividers

These metal dividers are noticeably corroded. They are called "plain" because, although there is a screw at the top for adjusting the width to which the dividers are set, there is no second screw or hairspring on one of the legs for refining the setting.
Description
These metal dividers are noticeably corroded. They are called "plain" because, although there is a screw at the top for adjusting the width to which the dividers are set, there is no second screw or hairspring on one of the legs for refining the setting. The short needle points are not removable. The upper part of the legs is indented, so that an oval is seen when the dividers are closed. The Brown University mathematics department donated these dividers to the Smithsonian in 1973.
Location
Currently not on view
date made
ca 1900
ID Number
MA.304722.03
accession number
1973.304722
catalog number
304722.03

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