Mathematics
1960s
Globetrotter Series ready reckoner calculating rule for mileage between British towns and gallons of petrol against price, by Blundell Rules Limited, Weymouth.
c.1820
Twelve inch wooden rule with tables for multiplication and the conversion of British measures and money, stamped "Bate London", c. 1820
c.1863
Ready reckoner "Prompt" calculator invented by Am. Maurand for converting between British Imperial Measure and the French Metric System, French, 19th century.
