Adding Machine Section, Comptometer Model C

This adding machine section has a glass case with a wooden base that holds a steel mechanism for two columns of white keys. The keys are covered with white plastic key tops that have both digits and complements of digits. The keys are alternately concave (odd digits) and flat (even digits). There are three decimal markers and two subtraction levers. Three number wheels are at the front, and a zeroing crank is on the right.
Felt & Tarrant Manufacturing Company began manufacturing the Model C Regular Comptometer in 1909 and the Model C Light Comptometer in 1911. It gave this section to the Smithsonian in 1912.
Currently not on view
Object Name
adding machine section
date made
ca 1910
Felt & Tarrant Manufacturing Company
Physical Description
steel (overall material)
glass (overall material)
wood (overall material)
plastic (overall material)
overall: 17.5 cm x 16 cm x 42.2 cm; 6 7/8 in x 6 5/16 in x 16 5/8 in
place made
United States: Illinois, Chicago
ID Number
catalog number
accession number
See more items in
Medicine and Science: Mathematics
Science & Mathematics
Adding Machines
Data Source
National Museum of American History, Kenneth E. Behring Center
Credit Line
Gift of Felt & Tarrant Manufacturing Company
Additional Media

Visitor Comments

Add a comment about this object

**Please read before submitting the form**

Have a comment or question about this object to share with the community? Please use the form below. Selected comments will appear on this page and may receive a museum response (but we can't promise). Please note that we generally cannot answer questions about the history, rarity, or value of your personal artifacts.

Have a question about anything else, or would you prefer a personal response? Please visit our FAQ or contact page.

Personal information will not be shared or result in unsolicited e-mail. See our privacy policy.

Enter the characters shown in the image.