Accession No
1882
Brief Description
Coggeshall’s rule, English, 18th C
Origin
England
Maker
Class
mathematics; calculating
Earliest Date
1700
Latest Date
1800
Inscription Date
Material
wood (boxwood); metal (brass)
Dimensions
length 313mm; breadth 38mm; thickness 7mm
Special Collection
Provenance
Purchased from Harriet Wynter, 345 Kings Road, Chelsea, London, SW3 5UU in 01/1974.
Inscription
Description Notes
Brass bound folding rule with brass shoulders and hinge; sector-type hinge.
Obverse: scale of inches divided [0] - [24] , numbered by 1, subdivided to 1/8. Scale of 1 1/4 inches, marked ‘1 1/4’, divided [1] - 0 - 7, numbered by 1, first division subdivided to 1/12.
Scale of 1 1/2 inches, marked ‘1 1/2’, divided [1] - 0 - 6, numbered by 1, first division subdivided to 1/12.
Reverse: upper limb has stock and slide set in. Log scale divided 1 - 10[0], numbered 1, 2, 3...1[0], 12, 2[0], 3[0]...10[0]; 1 - 8 subdivided to 0.1, 8 - 10 subdivided to 0.2, 10 - 20 subdivided to 0.5, 20 - 80 subdivided to 1, 80 - 100 subdivided to 2. This scale appears once on stock, marked ‘A’ and twice on the slider, marked ‘B’ and ‘C’. Further log scale on stock, marked ‘D’ and ‘Girt Line’, subdivided [4] - 40, numbered 5, 6...10, 12, 20, 30, 40; 4 - 10 subdivided to 0.1, 10 - 20 subdivided to 0.2; 20 - 40 subdivided to 0.5; points marked ‘WG’ (wine gallon) and ‘AG’ (ale gallon). Reverse of slide has scale of inches divided [0] - [12], numbered by 1, divided to 1/8.
Lower limb has scales for 1/4 inch, 1/2 inch, 3/4 inch and 1 inch. 1/4 inch is divided [1] - 0 - 38, numbered by 2 (1 also numbered); first division subdivided to 1/6. 1/2 inch scale divided [1] - 0 - 19, numbered by 1; first division subdivided to 1/12. 3/4 inch scale divided [1] - 0 - 12, numbered by 1; first division subdivided to 1/12. Inch scale divided [1] - 0 - 9, numbered by 1; first division subdivided to 1/12.
On fully extended outer edge of limbs: decimal foot scale divided [0] - 200, numbered by 10 (except 100), subdivided to 1.
Two brass pins to hold limbs together.
Condition good; complete
References
Events
Description
Scale Rule
A straight rule with a scale engraved along the length is the simplest instrument for making linear measurements, and has been used since antiquity. However, scale rules were not commonly used for making scale drawings until around 1550 in Northern Europe. Anthropomorphic dimensions such as the foot were commonly used for the scale.
Scale rules can be straight or folding and often have even scales on one side and diagonal scales on the other, which enable the user to divide any measurement into 100 parts. They were often decorated by the maker, demonstrating artistic as well as mathematical skills (although they became more purely functional from mid 18th century). They were usually made of brass, silver, ivory or boxwood.
FM:39553
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