Protractor Signed by Delure

This brass semicircular protractor is graduated by single degrees and marked by tens, from left to right and from right to left, from 10° to 180°. The degree lines are probably stamped rather than engraved by hand and thus represent a notable increase in workmanship over MA*326978 and MA*316861. Higher levels of accuracy were not reached until machine division was achieved by instrument makers such as Jesse Ramsden, who worked approximately fifty years after this protractor was manufactured.
The inner edge of the base of the protractor is slanted, and there is a notch at the origin point. The base carries a maker's mark: Delure À Paris. The protractor is very similar to one depicted in the famous manual on mathematical instruments by Jean-Baptiste Delure's son-in-law, Nicolas Bion. The protractor dates to about 1720. It was purchased in 1959 from the estate of Henry Russell Wray via an auction conducted by Maggs Bros. Ltd. of London.
References: Nicolas Bion, Traité de la construction et des principaux usages des instruments de mathematique (Paris, 1709), 25–27; Peggy Aldrich Kidwell, Amy Ackerberg-Hastings, and David Lindsay Roberts, Tools of American Mathematics Teaching, 1800–2000 (Baltimore: Johns Hopkins University Press, 2008), 166–168; Maya Hambly, Drawing Instruments: 1580–1980 (London: Sotheby's Publications, 1988), 120–121; Jean-Dominique Augarde, "La fabrication des instruments scientifiques du XVIIIe siècle et la corporation des fondeurs," in Christine Blondel et al., eds., Studies in the History of Scientific Instruments (London, 1989), 62–63.
Currently not on view
Object Name
date made
ca 1720
Delure, Jean-Baptiste-Nicolas
Physical Description
brass (overall material)
overall: .1 cm x 11 cm x 7 cm; 1/32 in x 4 11/32 in x 2 3/4 in
place made
France: Île-de-France, Paris
ID Number
accession number
catalog number
Science & Mathematics
See more items in
Medicine and Science: Mathematics
Data Source
National Museum of American History, Kenneth E. Behring Center
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