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History of Science Museum

Rectangular Protractor and Plain Scale, London, c.֫. 1730

Inventory Number 18805.1.6


Brief Description
A large format rectangular protractor of the first half of the 18th century. It has been attributed to the notable London maker Thomas Heath on the basis of the other instruments which it accompanied when acquired.
Item type
Object
Provenance
Presented by Howard Dawes.
Object type
Protractor
Dimensions
Height: 2mm Width: 305mm Depth: 73mm
Inventory No
18805.1.6

Description

Brass rectangle whose upper face has bevelled edges, with a protracting scale [0] - 180 divided to 5, 1 and ½° and numbered by 10, running in both directions. The raised portion is blank and surrounded by a band of leaf decoration.

The reverse carries an 11" diagonal scale, dividing an inch and a half inch into 100 equal parts. Separated by a band of leaf decoration are scales of equal parts 10, 15, 20, 25, 30, 35, 40, 45, 50 combined with two scales of chords C [0] - 90 to different radii.