Carpenter's 2-foot folding rule in boxwood with logarithmic slide, made by James Rabone & Sons, Birmingham, mid to late 19th century. This is a standard carpenter's rule of the period and includes scales for calculating the volume of wood and the p
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
The 'Tell Bell' educational game, made by Knapp Electrical Inc, a division of P. R. Mallory & Co. Inc.. An educational toy requiring the player to answer multiply choice questions involving mathematics. Answers are selected with template cards and
Mechanical ready reckoner patented by Patented by James Hines. This form of calculator gave costs of various quantities of goods at various prices per pound, hundredweight or ton. The quantity was set by turning the apropriate wheel at the side, and
A single surface model made by Alan Bennett in Bedford, 1995. It consists of a Klein bottle cut to form one single-twist Mobius strip. A Klein bottle is a surface which has no edges, no outside or inside and cannot be properly constructed in three di
A Klein bottle is a surface which has no edges, no outside or inside.
Brass sector (Gunter's pattern) by Elias Allen 1623. Allen made the sector to the design of Edmund Gunter who published a description of it in the same year. Sectors were used from the end of the 16th century until the mid 19th for calculations invol
Single surface models made by Alan Bennett in Bedford, 1995. Four small Klein bottles (left to right): i) one loop relating to the single-twist Mobius strip, ii) two loop relating to the three-twist Mobius strip, iii) three loops relating to the five
Napier's bones, cylindrical arrangement in wooden box with ten figured rollers; inside lid inscribed "This box was the identical property of the author of ye Logs, Napier 1824" from the library of the Lord Napier and Ettrick. This type of Napier's b
An exchequer tally dated 1822. The English Exchequer used tallies to record deposits from the mid-12th century until 1826. Notches show the amount paid; differently spaced notches standing for a penny, a shilling, £1, £20, £100 and £1000.