Gunner's quadrant and perpendicular by George Adams the Younger, c.1780. This instrument was designed primarily to ensure that a cannon or mortar was elevated to the required angle. Quadrants were also used for navigational purposes to determine the
Japanese soroban or abacus with 13 columns, each with 5 beads below the bar and one above.This represents an intermediate form between the original Chinese abacus and the modern Japanese type. This arrangement was common from the late 19th century u
Stylus-operated Indian currency adder, wooden backboard with handmade varnished card face inscribed 'R.G.W. 24.2.12'. The GEM calculator was originally patented in 1890 as a simple device for the addition of English money. Numbers are added by insert
McFarlane calculating cylinder, c1835. This is a ready reckoner inscribed with tables giving various percentages of various sums of money in sterling.
Napier's bones in brass, 17th century. John Napier (1550-1617), inventor of logarithms, also created this popular calculating tool known as Napier's cylindrical 'rods' or 'bones'. Napier's rods reduced muliplication to a sequence of simple additions
Replica made by E. Rognon, Paris of Blaise Pascal's first calculating machine of 1642, held by the Conservatoire National de Art et Metiers, Paris.The original machine was completed in 1642 when Pascal was only 19, to help his father in business. It
Planimeter (rolling type) by G. Coradi, Zurich, in case, 1886. Planimeters were used by engineers and scientists to measure the area inside a closed curve.
'Tachypoly Plasiasme' ready reckoner, 1880-1884. Invented by C L Chambon in 1880, the 'Tachypoly plasiasme' ready reckoner showed multiplication tables up to 100 times 100.
Set of 7 assembled cardboard geometrical models on wooden stands showing the surfaces of the second order.
A single surface model made in glass by Alan Bennett in Bedford, 1995. It consists of a Klein bottle with three loops, one of which has been cut away and sectioned to form a pair of single twist Mobius strips. A Klein bottle is a surface which has n