Instructions for Otis King's Pocket Calculator

This pamphlet folds out to eight pages and was printed on light green paper by Carbic Limited, the British manufacturer of Otis King's Pocket Calculator, a cylindrical slide rule. Carbic's address on the pamphlet—171, Seymour Place, London, W.I.—is scratched out and reprinted as 54, Dundonald Road, London, S.W.19. Dundonald Road was the last known location for Carbic, and the company was there by 1959. The calculator was available by mail order in 1960 for 62s. 6d. (roughly $175.00).
The pamphlet provides details of the scales on the Model K (which performed multiplication and division) and the Model L (which also provided readings of logarithms for determining roots and powers). The examples also include problems of proportion, percentages, constant factors, and calculations in pounds sterling (before decimalization of British currency). The last three pages provide instructions for operating the instrument.
See also 1987.0788.01 and 1987.0788.07.
Reference: "Finding the Answer is Simplicity Itself," advertisement for the Otis King Pocket Calculator, The New Scientist 5, no. 121 (March 12, 1959): 548 and 8, no. 213 (December 15, 1960): 1568.
Currently not on view
Object Name
date made
ca 1960-1962
Carbic Limited
Physical Description
paper (overall material)
overall: 20.2 cm x 13 cm; 7 15/16 in x 5 1/8 in
place made
United Kingdom: England, London
ID Number
accession number
catalog number
Rule, Calculating
Slide Rules
Science & Mathematics
See more items in
Medicine and Science: Mathematics
Slide Rules
Data Source
National Museum of American History, Kenneth E. Behring Center
Credit Line
Gift of Howard I. Chappelle

Visitor Comments

Add a comment about this object

**Please read before submitting the form**

Have a comment or question about this object to share with the community? Please use the form below. Selected comments will appear on this page and may receive a museum response (but we can't promise). Please note that we generally cannot answer questions about the history, rarity, or value of your personal artifacts.

Have a question about anything else, or would you prefer a personal response? Please visit our FAQ or contact page.

Personal information will not be shared or result in unsolicited e-mail. See our privacy policy.

Enter the characters shown in the image.