Comptograph with Typewriter

In the first half of the 20th century, a few companies manufactured accounting machines that could both type text and carry out routine calculations. This is an experimental combined typewriter and adding machine.
It has a cherrywood case and eight columns of metal key stems, with turquoise and white color-coded discs set in the metal key tops. Digits and complements of digits are shown on the discs. There are nine keys in each column. The cover under the keys consists of metal slats with holes drilled in them. There is one slat for each column of keys. A glass window at the front shows nine metal wheels that record totals. Only eight-digit entries and totals print. On the right side toward the front are a knob and a lever. Depressing the lever allows one to turn the knob and zero the total. Immediately to the right of the keyboard is a small lever that is pushed up to release the keys. Further to the right are two large buttons attached to levers. To the left at the front is another large button on a straight shaft.
Behind and above the keyboard is a typewriter with QWERTY keyboard. The type for the typewriter is below these keys. There is a lever on the upper left side of the typewriter carriage to shift the case of the letters and one on the upper right of the typewriter to slide the carriage left or right. At the back is a wide carriage, the printing mechanism for the adding machine, and a ribbon. There are two bells under the typewriter, one on top of each spool of the ribbon.
According to documentation, this machine was an experimental model of inventor Dorr E. Felt and never led to any patent or product. The coloring of the keys resembles that on Comptometer MA*248688, which dates from 1898 and Comptograph MA*323632, which dates from 1900.
Accession Journal, 1991.3107.06.
Currently not on view
Object Name
adding machine
date made
Felt & Tarrant Manufacturing Company
Physical Description
metal (overall material)
wood (overall material)
ceramic (overall material)
cloth (overall material)
rubber (overall material)
glass (overall material)
overall: 38 cm x 50 cm x 51.2 cm; 14 31/32 in x 19 11/16 in x 20 5/32 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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