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Details and Image

TypeModel No.MakerCountryConstruction
DateScale LengthArea of Use
Gilson Atlas Type 3
Enameled Aluminum
1931diam. 20 cmHigh-Accuracy Calculation

Notes: "Very long spiral scale (25 turns, altogether about 34.4 ft) allows very high-accuracy calculations for a slide rule. In the manual the length is reported as 50 ft, but this assumes (incorrectly) that all 25 turns have the same diameter as the outermost spiral."

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