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.
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
6 figure engine counter by Schaeffer and Budenberg of Manchester, 1888. The counter could be used to count revolutions of a piece of mechanism or reciprocating actions.
A single surface glass vessel made by Alan Bennett in Bedford, 1995. It consists of a five-layered sphere with added access routes which when cut produces a pair of single-twist Mobius strips. A Klein bottle is a surface which has no edges, no outsid
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
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
Wire model of a 'cylindroid' by Howard Grubb, Dublin in brass glazed cylindrical case on a wooden base. The model was made on the instructions of Robert Stawell Ball who wrote the definitive work 'A treatise on the Theory of Screws' in 1900. Thomas G
Playskool wooden toy, a wooden framework with rotating blocks bearing numbers and symbols to do arithmetic. 1960-1980. Toys to help with arithmetic were introduced from the start of the 20th century.
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
Brunsviga calculating machine with lid, no262. c.1892. This barrel calculating machine represents the Brunsviga in its earliest form. Barrel calculating machines were smaller, lighter and easier to operate than Arithmometers. The machine performs mu