Jean_LAMESCH_Sliderules_Collection_BOX_JL06

1689_GILSON_THE_BINARY_RULE_Type_III

1689_GILSON_THE_BINARY_RULE_Type_III

GILSON The Binary Rule Type III, US ca. 1950. Aluminium, 8.25" diameter. Instructions here. Article by Aldinger/Chamberlain here. No pouch, no case.