- Subject
- Calculation
- Item type
- Object
- Primary inscriptions
- Signed across the hinge "I P Fecit". The descender of the hinge is missing.
- Physical material
- Brass
- Object type
- Sector
- Dimensions
- Height: 245mm Width: 57mm Depth: 5mm
- Inventory No
- 46986
Description
Brass 9 inch sector with folding support strut. The rivets are unusually prominent. The pattern of scales is close to that established by Elias Allen but the engraving style is quite different from Allen and his apprentices; compare inv. 51763 by John Allen.
The signed side carries divided sectoral scales of equal parts (E pts) and solids (Soll:) and dotted scales of metals and regular polyhedra (straddling the legs). There is a single meridional scale (Mer). The reverse carries divided sectoral scales of sines (Si) and areas (Sup:), and dotted scales of polygons (straddling the legs) and an unlabelled scale (5 to 10). There is a single divided scale of tangents (Ta) and a dotted scale of secants (Se). One outer edge carries inches; the other may be logarithmic numbers.
