Wooden Box Model Comptometer

This key-driven non-printing adding machine has a wooden case and eight columns of color-coded plastic keys. The keys are black and white, with complementary digits indicated in red. It is a relatively late example of a Comptometer with a wooden, rather than a metal, case.
There is a spring around each key stem, and the stems become progressively longer as the digits are larger. Eight subtraction levers are in front of the keys. Eight decimal markers are attached to a metal plate, painted black, which is in front of these. A row of nine windows in the plate reveals the number wheels. Hence the machine can have eight-digit numbers entered and compute nine-digit totals. The zeroing mechanism is a knob and lever on the right side.
The serial number, stamped on the front of the machine under the decimal markers, is 5765. A metal tag attached to the back of the machine is marked: TRADE COMPTOMETER MARK (/) PAT’D (/) JUL.19.87 JUN. 11. 89. (/) OCT.11.87 NOV.25.90 (/) JAN.8.89 DEC.15.91. (/) SEP.22.96 (/) Felt & Tarrant Mfg. Co. (/) CHICAGO.
Compare to MA*323650.
Currently not on view
Object Name
adding machine
date made
ca 1906
Felt & Tarrant Manufacturing Company
Physical Description
plastic (overall material)
wood (overall material)
metal (overall material)
overall: 13.4 cm x 20.4 cm x 36.3 cm; 5 9/32 in x 8 1/32 in x 14 9/32 in
place made
United States: Illinois, Chicago
ID Number
catalog number
maker 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
Additional Media

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