The Smithsonian owns a number of protractors in addition to the 60 instruments discussed in this object group. For instance, the mathematics collection also has protractors in sets of drawing instruments, and it may have some additional combination instruments as well. Other NMAH units have protractors, and there are several at the National Air & Space Museum. Relevant books and trade literature (product catalogs) are found in the Smithsonian Institution Libraries. Some of these records are available through the Collections Search Center, with information added on an ongoing basis.

These museum databases also have notable protractor collections:

Further Reading

Ackerberg-Hastings, Amy. "Teaching Mathematics with Objects: The Case of Protractors." In Proceedings of the Twelfth International Congress on Mathematics Education, edited by Sung Je Cho et al. Seoul National University, 2012. 

———. "Protractors: Acute Solutions for Obtuse Students." In Tools of American Mathematics Teaching, 1800-2000, by Peggy A. Kidwell, Amy Ackerberg-Hastings, and David Lindsay Roberts, 165–180. Baltimore: The Johns Hopkins University Press, 2008.

———. "Rectangular Protractors and the Mathematics Classroom." In Hands on History: A Resource for Teaching Mathematics, edited by Amy Shell-Gellasch, 35-40. Mathematical Association of America Notes No. 72. Washington, DC, 2007.

———. "Protractors in the Classroom: An Historical Perspective." In From Calculus to Computers: Using the Last 200 Years of Mathematical History in the Classroom, edited by Richard Jardine and Amy Shell-Gellasch, 217-228. Mathematical Association of America Notes No. 68. Washington, DC, 2005.

Adler Planetarium. Webster Signature Database. 

Bennett, James A. The Divided Circle: A History of Instruments for Astronomy, Navigation and Surveying. Oxford: Phaidon and Christie's Limited, 1987.

Bion, Nicolas. Traité de la construction et des principaux usages des instruments de mathematique. Paris, 1709.

Chapman, Allan. Dividing the Circle: The Development of Critical Angular Measurement in Astronomy. 2nd ed. Praxis Publishing, 1995.

Daumas, Maurice. Scientific Instruments of the Seventeenth and Eighteenth Centuries and Their Makers. Edited and translated by Mary Holbrook. London: B. T. Batsford, 1972.

Dickinson, H. W. "A Brief History of Draughtsmen's Instruments." Transactions of the Newcomen Society 27 (1949–1951): 73–84.

Hambly, Maya. Drawing Instruments, 15801980. London: Sotheby's Publications, 1988.

Kiely, Edmond R. Surveying Instruments: Their History and Classroom Use. National Council of Teachers of Mathematics 19th Yearbook. New York: Bureau of Publications, Teachers College, Columbia University, 1947.

McConnell, Anita. Jesse Ramsden (1735-1800): London's Leading Scientific Instrument Maker. Ashgate, 2007.

Scott-Scott, Michael. Drawing Instruments. Shire Publications Ltd., 1986.

Stanley, William Ford. Mathematical Drawing and Measuring Instruments. 6th ed. London: E. & F. N. Spon, 1888.

Turner, Anthony. Early Scientific Instruments: Europe 1400–1800. London: Sotheby's Publications, 1987.

Warner, Deborah J. National Museum of American History Physical Sciences Collection: Navigation.

———. National Museum of American History Physical Sciences Collection: Surveying and Geodesy.

Watkins, J. Elfreth. "The Ramsden Dividing Engine." In Annual Report of the Board of Regents of the Smithsonian Institution . . . to July, 1890, 721–739. Washington, D.C.: Government Printing Office, 1891.

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