On Display

    Bissaker's slide rule, 1654, and Thacher's calculating instrument, 1881.

    The earliest known dated slide rule, made by Robert Bissaker, which uses scales bound together with metal bands.

     
    Henrici's harmonic analyser, No 3, 1894.

    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

     
    The 'Multiplicateur Enfantin' ready reckoner, c 1880.

    Automatic calculator: Chambon's "Multiplicateur Enfantin". The device shows multiplication tables up to 50 times 28.

     
    Quipu, South American, c 15th century.

    Replica of a quipu made from an original held at the Museum of Natural History, New York, in 1974. Quipus were used by the Incas during the 15th and early 16th centuries as records of all types of accounts. It was discovered in the early 20th century

     
    Gunnery callipers, French, 17th century.

    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

     
    GEM calculator, 1890.

    Gem' calculating machine, J.Guthrie's patent No 15062, 1890. The GEM calculator is a simple device for the addition of English money. Numbers are added by inserting a stylus against the figure and pulling downward.

     
    Klein bottle, 1995.

    A single surface model made by Alan Bennett in Bedford, 1995. It consists of three Klein bottles set inside each other sharing a common loop. When cut this gives a pair of single-twist Mobius strips. A Klein bottle has no edges, no outside or inside

     
    Model depicting face-centred cubic packing, 1975.

    Model to show face-centre cubic packing made of ping-pong balls.1975. This model imitates a stuctural form found in crystals.

     
    Klein bottle, 1995.

    A single surface model made by Alan Bennett in Bedford, 1995. It consists of a parallel sided coil with loops piercing the return tube which when theoretically cut gives a pair of 13-twist Mobius strips. A Klein bottle has no edges, no outside or ins

     
    Two Klein bottles, 1995.

    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