Issue No. 01 - January-March (2003 vol. 25)
Michael R. Williams , Computer History Museum
Erwin Tomash , Charles Babbage Institute
<p>The sector-also known as the proportional, geometric, or military compass-was an analog calculating instrument used widely from the late 16th century until modern times. The origins and usage of this commonly encountered instrument are not well known. This article provides historical background on the sector's invention and on its precursor instruments, and describes the uses for many of the scales commonly found on these instruments.</p>
M. R. Williams and E. Tomash, "The Sector: Its History, Scales, and Uses," in IEEE Annals of the History of Computing, vol. 25, no. , pp. 34-47, 2003.