Thacher's calculating instrument, with printed directions and rules for operating pasted to the upper surface of base. One of two wooden turning knobs is missing. A section of one of the feet on the bottom of the base is broken off.
Материал
"KEUFFEL & ESSER CO. N.Y."
On base: "4012" over "2562;" the maker's inscription stamp; and an eagle or hawk holding a circle in one claw, with "TRADEMARK."
Around one end of the drum: "Patented by Edwin Thacher, C. E. Nov. 1st, 1881." and "Made by Keuffel & Esser Co., New York."
