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Details and Image
Type
Model No.
Maker
Country
Construction
Material
Date
Scale Length
Area of Use
Circular and Spiral Slide Rules
LITHOCALCULATOR / Eckel Dial Rule
LITHOCALCULATOR Co.
USA
Metal/plastic
1950s
Ø 16.8 cm
General calculations
Notes:
This layman's model was designed Arthur Frederick Eckel post co-founding Pickett & Eckel. The revolutionary design incorporated an exotic but largely impractical way of locking/unlocking the cursor to make multiplication simpler.
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