## On Display

Nine inch brass sector, by Adams; engraved "Improv'd and made by Geo. Adams, Mathm. Inst. Maker to His Royal Highness, George Prince of Wales, London", in fishskin case. Sectors were used in calculations involving proportion. They contain logarithmic

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

Set of mathematical drawing instruments by G.Adams, in Sheraton case, oak and mahogany, mid 18th century. The case contains a sector, parallel ruler, pair of callipers, rectangular protractor, curve drawing instrument and compasses and dividers.

Gunners callipers, 6 inch by H.Gregory, brass 18th century. These callipers ere used for measuring the diameter of cannon balls, or by crossing the arms, the bore of a cannon..

A 2 foot boxwood slide rule for navigators, c.1800. 'Sliding Gunters' , or navigator's rules with a slide are comparatively rare, as most navigators preferred to stick with the ordinary 'Gunter' scale based on the combination of trigonometric, logari

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

Mechanical counting device, c 1900. Devices for counting the revolutions or repetitive actions of machines were developed from the mid 19th century.

Set of 'arithmetical scales' by Smith and Dolier, late 19th century. These 'scales' were used to set many different sums in addition and subtraction. Pupils in a class would probably have used slates to do the sums.

Calculating Rule 'Parker's Prestometer Tablet', c.1860 by Isaac Aston, London. One side of the rule is inscribed with multiplication tables involving halves.the other side has more complicated scales involving areas and volumes.

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 d