Comptometer Model A Section

This model has two columns of nine white plastic keys. Digits and complementary digits are indicated on the keys. Keys for odd digits are concave, those for even digits are flat. The mechanism is of steel and the two numeral wheels have white plastic rims. There are no subtraction levers, but there is a zeroing crank on the right. The entire model rests on a wooden base; there is no cover. The model was used as reference by Dorr E. Felt and J.A.V. Turck in developing the mechanism for production of the Model A Comptometer.
Felt & Tarrant, Accession Journal, 1991.3107.06.
Currently not on view
Object Name
adding machine section
date made
Felt & Tarrant Manufacturing Company
Physical Description
steel (overall material)
plastic (overall material)
wood (overall material)
overall: 15.5 cm x 13.2 cm x 36 cm; 6 3/32 in x 5 3/16 in x 14 3/16 in
place made
United States: Illinois, Chicago
ID 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
Gift of Victor Comptometer Corporation
Additional Media

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