overall: .8 cm x 12.3 cm x 3.3 cm; 5/16 in x 4 27/32 in x 1 5/16 in
This small, one-sided slide rule is made of wood. It has a white plastic layer on the front of both the base and the slide. The indicator is made from plastic. The base bears A, D, and K scales. The slide bears B, CI, and C scales. The scales are approximately 4-1/8 inches long. The slide is slightly longer than the base. The back of the slide rule is bare boxwood and has no scales.
The instrument is marked on the slide: MADE IN (/) ENGLAND. It closely resembles the 4-inch Jiffy slide rule made by Unique Slide Rule Company of Brighton, England. Unique sold slide rules from about 1923 to 1975.
References: Peter M. Hopp, <i>Slide Rules: Their History, Models, and Makers</i> (Mendham, N.J.: Astragal Press, 1999), 229–231; "British Slide Rules," <i>The Slide Rule Museum</i>, http://sliderulemuseum.com/British.htm; David M. Riches, <i>Mathematical Instruments: A Private Collection</i>, http://www.mathsinstruments.me.uk/page14.html; Peter Hopp, Colin Barnes, and John Knott, "Unique Slide Rules," <i>Journal of the Oughtred Society</i> 6, no. 1 (1997): 32–44.