R.C.Allen Model 35 Calculating Machine

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This ten-key, non-printing electric pinwheel calculating machine has a black metal frame that is painted green under the keys. Two rows of black plastic keys are in front, a metal bar is on the left, three registers are above the keyboard, and a rod with sliding decimal markers is above the result and revolution registers. One may enter numbers up to nine digits long, record up to eight digits in the revolution register, and computer results of up to 13 digits.
The machine has an electric cord.
A mark on the front reads: “World FAMOUS” [/] 10 KEY CALCULATOR (/) AMERICAN AND SWEDISH PATENTS. Another mark there reads: R.C. Allen (/) MODEL ‘35’. A mark on the back reads: R.C.Allen (/) 10 KEY (/) CALCULATOR (/) FACIT SYSTEM (/) R.C. ALLEN BUSINESS MACHINES, INC. (/) GRAND RAPIDS, MICH.,U.S.A. (/) PATENTED (/) MANUFACTURED IN THE UNITED STATES (/) LICENSED UNDER FACIT PATENTS. A mark on the bottom reads: 29433 (/) MODEL 35
R. C. Allen, Inc. (later R. C. Allen Business Machines) was founded by Ralph C. Allen (1884–1967) in Grand Rapids, Michigan, in 1932. By 1938 Allen was a distributor of Facit machines. It would distribute and manufacture cash registers, calculating machines, and typewriters. During World War II the firm began manufacturing aircraft instruments, and would come to focus on this business.
According to the donor, this machine was manufactured in 1948 and had an original cost of $397. It came from his personal collection of calculating machines.
American Office Machines Research Service, vol. 3, 1938.
Currently not on view
date made
R. C. Allen Business Machines, Inc.
place made
United States: Michigan, Grand Rapids
Physical Description
steel (overall material)
plastic (overall material)
overall: 16.8 cm x 28 cm x 25 cm; 6 5/8 in x 11 1/32 in x 9 27/32 in
ID Number
maker number
accession number
catalog number
Credit Line
Gift of William L. Jackson
See more items in
Medicine and Science: Mathematics
Science & Mathematics
Calculating Machines
Data Source
National Museum of American History


"I have a R C Allen Model 35 in working condition with cover and operating manual.I am interested in donating to an institution that may appreciate this machine.It has to work hard to add, subtract, multiply and dividebut it unerringly does so.My uncle bought it in the 1940'sand it was passed on to me.I used to play with it as a kid.Best"

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