Archive
of
Collections
Details and Image
Type
Model No.
Maker
Country
Construction
Material
Date
Scale Length
Area of Use
Pocket Watch Slide Rules
Halden / Calculex Type 2
Halden (Joseph)
UK
Metal/glass/paper
1920-1938
Ø 6.2 cm
Basic Calculations
Notes:
Elegant pseudo (no crown winder) pocket-watch style slide rule that over many years evolved into several distinct types.
Image 1
Image 2
Image 3
Image 4
Image 5
Image 6
Image 7
Image 8
