Howlett Protractor Signed by Elliott Bros.


In 1837, Samuel Burt Howlett (1794–1874), chief draftsman to the Board of Ordnance in Great Britain, described a semicircular protractor for use in plotting surveys. The instrument overcame perceived shortcomings with utilizing circular protractors or theodolites in rustic field conditions. He indicated his design had already been available for purchase for a few years. Indeed, by 1847, treatises and textbooks on surveying, military engineering, and mathematical instruments widely discussed the "Howlett Protractor."

This example is in the standard semicircular form and is made of brass. The protractor measures 23 cm by 11 cm. It is graduated to half-degrees and marked by tens from 0° to 180° and from 180° to 360°, both in the clockwise direction. There are notches on the interior of the protractor at 0, 90, and 180 degrees. There is an arm fastened to the origin point. The arm bears a vernier scale marked by fives from 15 to 25, then from 5 to 15. There is a thumb-screw on the vernier; two more thumb-screws with pointer tips are on the base of the protractor and are for securing the protractor to a surveying or engineering drawing.

The base of the protractor bears a maker's mark: Elliott Bros. (/) LONDON. Frederick and Charles Elliott gave this name to their firm in 1854, after four years of partnership with their father, the instrument maker William Elliott. However, they did not start using this form of signature on their products until 1873. This object thus dates between 1873 and 1916, when the firm changed its signature to "Elliott Bros (London) Ltd" and focused on electrical devices rather than drawing instruments. The protractor is stored in its original wooden case, which is lined with blue velvet. Two brass hooks secure the lid. "Not R. Blu" is written in blue pencil on the bottom of the case.

References: Samuel B. Howlett, "A New Method of Plotting a Survey," Papers on Subjects Connected with the Duties of the Corps of Royal Engineers 1 (1837): 65–67; Howlett Papers, Additional Manuscripts 871–884, Durham University Library, Archives and Special Collections, Durham, England; Basil Jackson, A Treatise on Military Surveying, 3rd ed. (London, 1847), 55–61; Gloria Clifton, “An Introduction to the History of Elliott Brothers up to 1900,” Bulletin of the Scientific Instrument Society 36 (1993): 2–7; H. R. Bristow, “Elliott, Instrument Makers of London. Products, Customers and Development in the 19th Century,” Bulletin of the Scientific Instrument Society 36 (1993): 8–11; H. R. Bristow, "Lewisham to Oxford: The Elliott Archive and Instrument Collection," Bulletin of the Scientific Instrument Society 109 (2011): 14–15; James Stewart, "On the Use of the Semicircular Protractor, with a Description of an Improved Form of that Instrument," Transactions and Proceedings of the New Zealand Institute 3 (1870): 316–318.

Date Made: 1873-1916

Maker: Elliott Bros.

Location: Currently not on view

Place Made: United Kingdom: England, London

Subject: MathematicsProtractorSurveying


See more items in: Medicine and Science: Mathematics, Science & Mathematics, Protractors


Exhibition Location:

Credit Line: Gift of Mrs. Russell Monroe

Data Source: National Museum of American History

Id Number: MA.314902Accession Number: 212171Catalog Number: 314902

Object Name: protractor

Physical Description: velvet (overall material)hardwood (overall material)brass (overall material)Measurements: overall: 4 cm x 27 cm x 13 cm; 1 9/16 in x 10 5/8 in x 5 1/8 in


Record Id: nmah_904311

Our collection database is a work in progress. We may update this record based on further research and review. Learn more about our approach to sharing our collection online.

If you would like to know how you can use content on this page, see the Smithsonian's Terms of Use. If you need to request an image for publication or other use, please visit Rights and Reproductions.