1868 C.H. Webb "The Adder" Calculator

C.H. Webb "The Adder," an early two-disc brass mechanical adding machine mounted on a shaped wooden base. Manufactured by C.H. Webb, New York, and marked "THE ADDER PAT'D MARCH 10TH 1868." The device consists of two interconnected metal dials, with the larger wheel numbered 0 to 99 and the smaller wheel numbered 0 to 49 representing hundreds. The mechanism incorporates an automatic tens-carry. Calculations are performed by rotating the dials with a stylus inserted into the holes around each dial; stylus is not included. Serial numbered 5371 on the reverse. Overall approx. 4.75" x 6.75". Brass face exhibits age-related patina, oxidation, spotting, scratches and surface wear; wooden backing shows general wear. Appears to be missing three small screws along the brass edges. Estimate $200 - $300

估價:$200

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