- Subject
- Mathematical instruments
- Item type
- Object
- Provenance
- Presented by J. A. Billmeir.
- Physical material
- Gilt brass and steel
- Object type
- Protractor
- Dimensions
- Diameter: 300mm Height: 91mm Width: 329mm Depth: 273mm Weight: 0.5kg
- Inventory No
- 47382
- Accession Number
- 1957-84/258
Description
Open semicircle with degree (0 to 180) and polygonal (3 to 24) scales, diametric bar with linear scale (0 to 200), pair of elaborate sights adjustable over vertical scales, shaped and decorated pivoted alidade with similar scale, pivot arranged to leave the central point of the semicircle free, one similar sight (one missing). Mechanical subdivision of the degree scale, its motion moving a blued steed index over a subsiduary scale on a moving disc..
