Turck Model 510 Comptometer

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In the early 20th century, inventors strove to adapt a variety of adding machines to electrical power sources. This experimental model represents an early attempt of Felt & Tarrant Manufacturing Company to do this for the Comptometer.
This full-keyboard non-printing adding machine has a metal case, painted black. It has seven columns of digit keys and eight recording wheels for results. A single column of nine blue plastic keys is on the left. Complementary digits are indicated on the keys. The keys are alternately concave (odd digits) and flat (even digits). Subtraction levers are just in front of the keys, then a row of seven decimal markers, and, in front of these, a row of eight windows. An “ADD. / MULT.” lever is at the back left of the machine. A zeroing lever is on the right side, and a crank at the back is used to provide power.
When the machine is set on “mult.,” one presses a number to be multiplied on the black and white keys, and the digit by which it is to be multiplied, on the blue keys. One then turns the crank at the back a number of times equal to the multiplier (alternately, this crank could be turned by an outside motor). When one has completed the sequence, all the keys pop up. In adding, one presses down a number to be added, turns the crank at the back entering the number, presses down another number, and turns the crank to complete the addition (again, the turning of the crank could be replaced by the action of a motor). This machine was never produced, although the “rock frame” was used in the Model H Comptometer and became a standard feature of later Comptometers.
The model was in the collections of Felt & Tarrant Manufacturing Company and donated to the Smithsonian by the successor firm of Victor Comptometer Corporation.
Felt & Tarrant, Accession Journal 1991.3107.06. The machine is Catalogue No. 75.
U.S. Patent 1371954, granted to J. A. V. Turck on March 15, 1921.
Currently not on view
date made
Felt & Tarrant Manufacturing Company
place made
United States: Illinois, Chicago
Physical Description
steel (overall material)
plastic (overall material)
wood (overall material)
overall: 12 cm x 26 cm x 31 cm; 4 23/32 in x 10 1/4 in x 12 7/32 in
ID Number
catalog number
accession number
Credit Line
Gift of Victor Comptometer Corporation
See more items in
Medicine and Science: Mathematics
Science & Mathematics
Adding Machines
Data Source
National Museum of American History


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