Comptometer Model J

This key-driven adding machine had ten columns of color-coded green and white plastic keys. Complementary digits were indicated on the keys, and they were alternately concave (for odd digits) and flat (for even digits). Another key stem is at the back to the right of the number keys. In front of the keys is a row of ten subtraction levers. In front of these is a row of ten numbered decimal markers. In front of these are windows in the metal case that reveal 11 number dials, that indicate the result of addition.
The machine is marked on the front top at the left: J329139. It is marked on the front: Comptometer. It is marked on a sticker on the left side: DEPARTMENT OF AGRICULTURE (/) 89699-BAE.
This instrument came to the Smithsonian from the U.S. Department of Agriculture.
Felt & Tarrant, Accession Journal 1991.3107.06
Currently not on view
Object Name
adding machine
date made
Felt & Tarrant Manufacturing Company
Physical Description
wood (overall material)
metal (overall material)
plastic (overall material)
overall: 14 cm x 27.5 cm x 37.5 cm; 5 1/2 in x 10 13/16 in x 14 3/4 in
place made
United States: Illinois, Chicago
ID Number
maker number
catalog number
accession number
Science & Mathematics
Adding Machines
See more items in
Medicine and Science: Mathematics
Adding Machines
Data Source
National Museum of American History, Kenneth E. Behring Center
Credit Line
Transfer from US Department of Agriculture

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