Protractors - Surveying
Since the first protractors appeared near the turn of the 17th century, around the same time that the technique of triangulation was developed for surveying, their utility for this activity appeared evident from early on. Surveyors typically carried at least one protractor in their field kits. The instrument might be combined with another drawing instrument, such as a set of parallel rules. By the 19th century, makers tried to blend convenience with multi-functionality, offering rectangular protractors that fit easily in a case or pocket and that were packed with aids for reducing real-world distances to proportional scales. They also showed off their improving craftsmanship with fine objects that retained accuracy in measurement. (See also the page on Engineering & Drafting.)
"Protractors - Surveying" showing 1 items.
- 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
- date made
- ca 1720
- Delure, Jean-Baptiste-Nicolas
- ID Number
- accession number
- catalog number
- Data Source
- National Museum of American History, Kenneth E. Behring Center