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History of Science Museum

Surveyor's Folding Rule, by Humfrey Cole, London, 1575

Inventory Number 49631


Acknowledgement: © History of Science Museum, University of Oxford, inv.49631

Subject
Surveying
Item type
Object
Provenance
Purchased.
Primary inscriptions
"* Humfrey . Cole . 1575 *"
Physical material
Brass
Object type
Rule
Dimensions
Height: 332mm Width: 62mm Depth: 5mm Weight: 0.85kg
Inventory No
49631
Accession Number
1950-41

Description

This is one of four surviving instruments of similar design by the leading English instrument maker of the 16th century.

Developed from a simpler craft instrument, the wooden 'carpenter's rule', Humfrey Cole's device is a multipurpose instrument that could be used for surveying, map work and specialised calculation. It incorporates an inch ruler and scales of equal parts, as well as scales for reckoning areas and volumes. When equipped with sights it could be used to measure horizontal angles and, with the further addition of a plumb bob, vertical angles can be taken with its quadrant and shadow square.

Produced in expensive brass and neatly engraved, it demonstrates both the engagement of mathematical practitioners with practical tasks and also their distance from the humble instruments of craft practice.