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Details and Image
Type
Model No.
Maker
Country
Construction
Material
Date
Scale Length
Area of Use
Pocket Watch Style
Halden's Calculex (v1)
Halden
England
Metal & Glass
1910-1930's
dia. = 6.1 cm
General Purpose
Notes:
1) Scales on both sides with inner moving scale 2) Came with a 94 page 5.7 cm x 5.7 cm instruction manual
Image 1
Image 2
Image 3
Image 4
Image 5
