The Locke Adder is a row adder using alternating fixed and moveable horizontal bars; carrying from one column to another is manual. The nine moveable slides show either red or green while in the zero position, and expose either silver or yellow as the slides are moved to the right. Between the slides are eight fixed bars, painted black with white numbers from 1 to 9. Locke Adders were on the market for less than ten years, probably being supplanted by dial adders such as the Calcumeter and the Calculator.
09-018A. THE LOCKE ADDER & BOX - 'Patented Dec. 24, 1901, Jan. 3, 1905'
American, 'Patented Dec. 24, 1901, Jan. 3, 1905', and stamped on the front face "THE LOCKE ADDER" and "C.E. LOCKE Mfg. Co., KENSETT, IOWA, U.S.A." Made of embossed sheet metal, 10 7/8" x 4" x 1/2", with original green felt backing. This Locke Adder is in very good overall condition in its original somewhat worn cardboard box, showing some hand wear to the black finish on the face.
09-018B. THE LOCKE ADDER -
'Patented Dec. 24, 1901'
American, 'Patented Dec. 24, 1901', and stamped on the front face "THE LOCKE ADDER" and "C.E. LOCKE Mfg. Co., KENSETT, IOWA, U.S.A." Made of embossed sheet metal, 10 7/8" x 4" x 1/2", with original green felt backing. This Locke Adder is in uncommonly fine overall condition, showing virtually no wear.
