On Display

'Magic Brain' calculator, c 1960.

Magic Brain' calculator made by Chadwick in tin and plastic, with stylus and instructions. C.1955. Very similar to the Exaxctus and other stylus calculators of the period, the Magic Brain could add, subtact, and multiply and duivide by repeated addit

 
Exactus stylus-operated adding and subtracting device, 1955-1965.

Exactus stylus-operated adding and subtracting device, with swivelling half plate for add and subtract options, marked "Mini-Add Made in England", c. 1950. The Exactus is one of several simple stylus-operated calculators to have been popular in the

 
'Little Professor' electronic calculator, 1980.

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

 
Klein bottle, 1995.

A single surface model made by Alan Bennett in Bedford, 1995. It is a toroid Klein bottle with disguised pierce which when cut produces a pair of single-twist Mobius strips. A Klein bottle has no edges, no outside or inside and cannot be properly con

 
Calculating scale, 1807.

Ready reckoner, boxwood weighted with brass, for gross and tare weights of ship's cargoes, engraved "Robert Ludgate, Custom House, London, 1807". Tare is the weight of the packaging or container. Scales are given for finding the gross weight if the

 
Klein bottle, 1995.

A single surface glass vessel made by Alan Bennett in Bedford, 1995. It consists of a five-layered sphere, extension of the three Klein bottles above to infinity which when cut gives a pair of single-twist Mobius strips. A Klein bottle is a surface w

 
Klein bottle, 1995.

A single surface model made by Alan Bennett in Bedford, 1995. It consists of a sphere with three interlinked loops the equivalent of three interconnected Klein bottles. A Klein bottle has no edges, no outside or inside and cannot be properly construc

 
Klein bottle, 1995.

A single surface glass vessel made by Alan Bennett in Bedford, United Kingdom. It consists of three Klein bottles in a column which when cut form a pair of single-twist Mobius strips. A Klein bottle is a surface which has no edges, no outside or insi

 
'Way-in-way-out vessel', 1995.

A single surface model made by Alan Bennett in Bedford, 1995. This 'way-in-way-out vessel' is equivalent to two Klein bottles, one inverted, sealed together back-to-back. When cut it forms two pairs of single twist Mobius strips. A Klein bottle is a

 
Klein bottle, 1995.

A single surface glass vessel made by Alan Bennett in Bedford, 1995. It consists of three columns of three Klein bottles interconnected, which when cut form three pairs of single-twist Mobuis strips, one of each pair being seperate, the other of each