Accession No

3667

Brief Description

‘The Pocket Adding Machine’

Origin

Maker

Class

calculating

Earliest Date

Latest Date

Inscription Date

Material

metal

Dimensions

length 121mm; breadth 77mm

Special Collection

Provenance

Donated, 16/12/1987.

Inscription

‘THE POCKET ADDING MACHINE’

Description Notes

Thin metal plate with 5 holes under a ‘£’, 2 under ‘Sh’ and 2 under ‘d’. Each hole shows a single digit. Below are grids exposed through slits with numbers by the side. From left to right (ie. £ to d), the numbers are 0-9 by 1; 0-9 by 1; 0-9 by 1; 0-9 by 1; 0-1 by 1; 0-9 by 1; 0-11 by 1 and 0-3/4 by 1/4. The grids can be moved to alter the digits above.

Condition: fair.

References

Events

Description
Mechanical adding machine
Early mechanical adding machines consisted of a keyboard on which to enter the numbers, a level to be pulled to add them (or pushed to subtract them), and an accumulator to display the results. The accumlator was a set of geared wheels, with numbers 0 to 9 printed around their circumferences, and each wheel corresponding to a decimal place. Each time a wheel made a full rotation, the next decimal place up moved round by one. This basic mechanism remained very similar until the mid 1960s.

18/10/2002
Created by: Saffron Clackson on 18/10/2002

FM:40481