Harmonic analyser designed by O.Henrici, made by G. Coradi, 1894. Harmonic analysers were designed to break down a complex wave, such as a sound wave, into its fundamental and harmonic components. This one uses the motions of three glass spheres whic
Set of Napier's bones in boxwood, in a boxwood case. John Napier (1550-1617), discoverer of logarithms, also created this popular calculating tool known as Napier's cylindrical 'rods' or 'bones'. Napier's bones reduced muliplication to a sequence of
Automatic calculator: Chambon's "Multiplicateur Enfantin". The device shows multiplication tables up to 50 times 28.
Callipers, used for artillery purposes, French, 17th century. Callipers were used to measure the diameter of cannon balls and the bores of cannons. This example also containd scales for artillery calculations
Napier's bones, cylindrical type, late 17th century. John Napier (1550-1617), discoverer of logarithms, created the popular calculating tool known as Napier's rods or bones. Napier's rods reduced muliplication to a sequence of simple additions; divis
Single surface glass vessel made by Alan Bennett in Bedford, 1995 The triple loop Klein bottle when cut gives a pair of five-twist Mobius strips. A Klein bottle is a surface which has no edges, no outside or inside and cannot properly be constructe
The Sinclair Executive Electronic Pocket Calculator (cutaway for exhibition) was the first electronic pocket calculator that could really fit into a pocket. Clive Sinclair (b. 1940) was able to achieve this by reducing the power input demanded by the
Harding's improved counter by Harding, Richardson, Rhodes and Co. Ltd., Leeds. Revolution counters were devised to keep a record of the operation of machinery.
Numeric Demonstrator', an elementary teaching aid patented by Ethel Linay in about 1900.. This elementary arithmetical teaching apparatus consists of ten wooden rods with squared paper pasted on them in order to show multiplication visually.
S & N adding machine by Seidel & Naumann, Dresden, serial no. 2398, in fitted box with stylus and instructions. The Seidel and Naumann adding machines used chain drives and a stylus. The numbers to be added were pulled down to the base bar and then a