
4 0 c m
34cm
actual image size: 26cm x 32cm
Description
The GEM calculator is a simple device for the addition of money. Numbers are added by inserting a stylus against the figure and pulling downwards. The design for this calculator was patented by J Guthrie in 1890 (patent no 15062).
Image Details
Image Ref.
10327833
© Science Museum / Science & Society Picture Library