Johnston Adding Machine, Model A11


This gray mechanical 10-key adding machine was manufactured by Johnston Adding Machine Company of California. It is a model A11 Adder with 10 white number keys and 6 red function keys. The machine could add, subtract, and multiply as well as print a paper tape. Its cover is hinged and opens to reveal the calculating mechanisms, the ribbon and platen for printing, and a red knob for advancing the printing paper. Stamped on a metal plate located on the inside right rear is the serial # 11766A11.

Johnston Adding Machine Company was acquired by the Marchant Calculating Machine Company in 1957. The Johnston plant was engaged to produce and distribute the Marchant 10-key adding machine.

See also: 1979.3084.128 Advertisement for Marchant's new adding machine.

1979.3084.023 - .025 Marchant Board of Directors Minutes of Meetings.

Date Made: ca 1956

Maker: Johnston Adding Machine Company

Location: Currently not on view

Subject: Mathematics


See more items in: Medicine and Science: Mathematics, Science & Mathematics


Exhibition Location:

Credit Line: Ernest Eldon Jorgenson

Data Source: National Museum of American History

Id Number: 2017.0315.01Model Number: A11Accession Number: 2017.0315Catalog Number: 2017.0315.01

Object Name: adding machine

Physical Description: metal (overall material)plastic (overall, keys material)Measurements: overall: 19.5 cm x 22.5 cm x 35.5 cm; 7 11/16 in x 8 27/32 in x 13 31/32 in


Record Id: nmah_1867907

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