A single surface glass vessel made by Alan Bennett in Bedford, 1995. Its form is a variation on the Klein bottle with an inlet passing through the vessel which when cut forms a pair of single-twist Mobius strips. A Klein bottle is a surface which has
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
Rectangular protractor in brass, engraved "Dollond, London", late 18th century.As well as the usual angular scale the instrument contains a diagonal scale for plotting distances on a map or plan.
Little Professor' calculator, children's working educational toy / game, 1980. Electronic calculators were now low cost available items which could be targetted at children and those with straightforward requirements. This example was exhibited in th
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
Electronic Pocket Calculator by Isot, model Elka 101, c1976. Before the fall of the Iron Curtain in 1989, Bulgaria hasd one of the largest electronics industries in Eastern Europe. However in the 1970s they had to import the integrated circuits to co
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
Consul' the Educated Monkey. A mathematical toy calculator patented by William Robertson in 1916 and made by the Educational Novelty Company of Dayton, Ohio, USA. When each of the monkey's feet are moved to point at two numbers, the monkey's hands m