Halden Calculex

---

Country of manufacture: England,            Date of manufacture: ____
Diameter: 6.2 cm,          Thickness: 1.1 cm,           Weight: 69.7 gms
Materials: German silver outer ring; glass lens on front and back sides
Cursor: engraved onto inner side of glass faces; one line on front and back
Scales: 8
Front: Linear scale (an 'L' scale), A (single cycle log scale) [ B (single cycle log scale), C (2-cycle log scale for square & square roots, arranged on 2 circles)]
Back: Scale of angles , A (single cycle log scale) [ B inverted (single cycle log scale; i.w., a 'CI' scale), a 3-cycle log scale for determing cubes and cube roots, arranged on 3 circles
Gauge Marks: [π ]
Condition: C3-C4 (Very minimal to Minimal signs of use)
Came with: Aluminum case and leather-bound instruction booklet

---

  

---