Pocket calculator
The Otis King's Pocket Calculator
Name/Title
Pocket calculatorEntry/Object ID
2025.1.157Description
Otis King's Patent Pocket calculator. Scale N423.Context
Cylindrical Pocket Slide Rule with Helical Scales, Made in England by Carbic Ltd., London 1921-1972. Patent 183723. It was designed by Otis Carter Formby King (1876–1944) who was a grocer and electrical engineer. King joined the manufacturing company Carbic Ltd for the purpose of making the Pocket Calculator. The long scale gave better resolution, even though accuracy was compromised by misprints and warping, it still gave a reading of one part in two thousand.Category
Domestic