Archive of Collections



Details and Image



Item#TypeModel No.Match No.Variant No.Model NameMakerCountryProduction or Serial No.MaterialScale LengthDateCondition
KEU390Linear
Mystery
Unknown
n/a
Mystery PolyphaseKeuffel & EsserUSA
460528
Engine divided celluloid laminated mahogany
"20"
1934
C4

Notes: "Mystery 20" sliderule with same scales as front side of K&E model 4088 and USBS Circular 47 version of conversion table. Back of slide has a peculiar scale of unknown purpose - graduated in degrees and minutes from 31 34' to 0, then 33 30" to 31 34'."

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