Comptometer Model C, Light

This full-keyboard non-printing adding machine has a gray-brown metal case and sits on a rectangular wooden base. There are eight columns of black and white color-coded plastic keys, with complementary numbers indicated on the keys. Keys for odd digits are concave, and those for even digits are flat. At the front of the machine are eight subtraction levers and eight decimal markers, as well as nine windows that reveal the totals shown on numeral wheels below. The zeroing handle is on the side.
The machine is marked on the left front with serial number: 47412. A metal tag behind the keys has several patent dates, the most recent being: SEP. 19. 11.
Currently not on view
Object Name
adding machine
date made
Felt & Tarrant Manufacturing Company
Physical Description
metal (overall material)
wood (overall material)
plastic (overall material)
overall: 17 cm x 25 cm x 38.8 cm; 6 11/16 in x 9 27/32 in x 15 9/32 in
place made
United States: Illinois, Chicago
ID Number
accession number
maker number
catalog 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 Felt & Tarrant Manufacturing Company

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