Slide rule (Simple English Wikipedia)

At least one circular rule, a 1931 Gilson model, sacrificed some of the scales usually found in slide rules in order to obtain additional resolution in multiplication and division. It functioned through the use of a spiral C scale, which was claimed to be 50 feet long and readable to five significant figures. See http://www.sphere.bc.ca/test/gilson/gilson-manual2.jpg Archived 2006-12-30 at the Wayback Machine. A photo can be seen at http://www.hpmuseum.org/srcirc.htm Archived 2009-01-25 at the Wayback Machine. An instruction manual for the unit marketed by Dietzgen can be found at http://www.sliderulemuseum.com/SR_Library_General.htm Archived 2007-02-14 at the Wayback Machine All retrieved March 14, 2007.

mccoys-kecatalogs.com (Global: low place; Simple English: low place)

"Fisher sizing rules". natgasedu.com. Archived from the original on 6 January 2010. Retrieved 2009-10-06.

At least one circular rule, a 1931 Gilson model, sacrificed some of the scales usually found in slide rules in order to obtain additional resolution in multiplication and division. It functioned through the use of a spiral C scale, which was claimed to be 50 feet long and readable to five significant figures. See http://www.sphere.bc.ca/test/gilson/gilson-manual2.jpg Archived 2006-12-30 at the Wayback Machine. A photo can be seen at http://www.hpmuseum.org/srcirc.htm Archived 2009-01-25 at the Wayback Machine. An instruction manual for the unit marketed by Dietzgen can be found at http://www.sliderulemuseum.com/SR_Library_General.htm Archived 2007-02-14 at the Wayback Machine All retrieved March 14, 2007.

http://www.sphere.bc.ca/test/circular-man2.html Archived 2007-04-02 at the Wayback Machine, instruction manual pages 7 & 8. Retrieved March 14, 2007.
At least one circular rule, a 1931 Gilson model, sacrificed some of the scales usually found in slide rules in order to obtain additional resolution in multiplication and division. It functioned through the use of a spiral C scale, which was claimed to be 50 feet long and readable to five significant figures. See http://www.sphere.bc.ca/test/gilson/gilson-manual2.jpg Archived 2006-12-30 at the Wayback Machine. A photo can be seen at http://www.hpmuseum.org/srcirc.htm Archived 2009-01-25 at the Wayback Machine. An instruction manual for the unit marketed by Dietzgen can be found at http://www.sliderulemuseum.com/SR_Library_General.htm Archived 2007-02-14 at the Wayback Machine All retrieved March 14, 2007.

http://www.sphere.bc.ca/test/circular-man2.html Archived 2007-04-02 at the Wayback Machine, instruction manual pages 7 & 8. Retrieved March 14, 2007.
"Fisher sizing rules". natgasedu.com. Archived from the original on 6 January 2010. Retrieved 2009-10-06.
At least one circular rule, a 1931 Gilson model, sacrificed some of the scales usually found in slide rules in order to obtain additional resolution in multiplication and division. It functioned through the use of a spiral C scale, which was claimed to be 50 feet long and readable to five significant figures. See http://www.sphere.bc.ca/test/gilson/gilson-manual2.jpg Archived 2006-12-30 at the Wayback Machine. A photo can be seen at http://www.hpmuseum.org/srcirc.htm Archived 2009-01-25 at the Wayback Machine. An instruction manual for the unit marketed by Dietzgen can be found at http://www.sliderulemuseum.com/SR_Library_General.htm Archived 2007-02-14 at the Wayback Machine All retrieved March 14, 2007.
The Log-Log Duplex Decitrig Slide Rule No. 4081: A Manual Archived 2009-02-14 at the Wayback Machine, Keuffel & Esser, Kells, Kern, and Bland, 1943, p. 92.