Burroughs Sample Calculator, Hours and Minutes

In 1911, the Burroughs Adding Machine Company introduced a key-driven adding machine much like the Comptometer produced by Felt & Tarrant Manufacturing Company. The Burroughs calculator, as the new machine was called, performed ordinary decimal arithmetic, like most adding machines. Burroughs inventors soon designed special versions of the calculator to solve other problems. This is a model or sample of one of them.
The machine adds hours and minutes. It has five columns of black and red color-coded plastic keys. Three columns have nine black keys, one right of these has five red keys, then the rightmost column has nine red keys. The two red columns represent minutes and tens of minutes, with carrying when the total reaches 60. Left of the number keys is a single key that is used to zero the leftmost numeral wheel. The keyboard is painted green. Six numeral wheels at the front of the machine show the result. Hours are represented on black wheels, and minutes on red ones. The machine has a black metal frame and four rubber feet. The fabric cover is painted black. One black key is missing, as are at least two screws for the case.
A red paper tag attached to the machine reads: PATENT DEPT. (/) #230. A white tag attached to the machine reads: 50500 (/) Dept Model (/) 363 (/) Hr & Min (/) Apr 24 (/) lpc. Another white tag attached to the machine reads: Reference Machine (/) 5 Columns (/) Hours & Minutes. A metal tag attached to the object reads: DONATED TO (/) The Smithsonian Institution (/) by (/) Burroughs Corporation.
Models 1982.0794.44, 1982.0794.45 and 1982.0792.46 are all from Burroughs Patent Dept. model 230. This object is the leftmost one in the photographs.
Currently not on view
Object Name
adding machine model
date made
ca 1920
Burroughs Adding Machine Company
Physical Description
plastic (overall material)
paper (overall material)
glass (overall material)
metal (overall material)
overall: 12.3 cm x 16 cm x 28.6 cm; 4 27/32 in x 6 5/16 in x 11 1/4 in
place made
United States: Michigan, Detroit
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 Burroughs Corporation
Additional Media

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