"Calculex" Circular Slide Rule
Halden's 'Calculex' patent circular slide rule in silver case.
Details
- Category:
- Mathematics
- Object Number:
- Y1981.20.1
- Materials:
- silver (metal) and glass
- Measurements:
-
overall: 15 mm x 63 mm x 84 mm,
- type:
- slide rule
- credit:
- Gift of Mr. P.F. Lee