3 0 c m
40cm
actual image size: 32cm x 22cm
Description
John Napier (1550-1617), discoverer of logarithms, also created this popular calculating tool known as Napier's cylindrical 'rods' or 'bones'. Napier's rods reduced multiplication to a sequence of simple additions and could also be used for division and to calculate square roots.
Image Details
Image Ref.
10306291
© Science Museum / Science & Society Picture Library