Pinwheel calculators were invented in the 1870s. These mechanical devices could be used for adding, subtracting, multiplying and dividing. They were expensive and hard to use, but would have been invaluable for Bank of England staff who previously had to perform complex calculations by hand.
Photographs show machines of this type still in use in the Bank in 1965. It was not until inexpensive electronic calculators came into common use in the 1970s that pinwheel calculators stopped being manufactured.
1870's
Metal, wood
1982/002
Image and text are copyright of Bank of England.