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arithma addiator wm sm

The history of pocket adding machines goes back to the 19th century.  One of the first commercially successful pocket adding machines was the “arithmographe” invented by Louis Troncet.  His adding machine was so successful that when other companies started producing machines based on his ideas they were called “Troncet-type calculators”.  Various Troncet-type adding machines were made into the 1970’s.

The Arithma, by Addiator, was one such device.  Using a set of numbered sliders encased in a metal shell and moved by means of a stylus, the Arithma could add and subtract quickly, quietly, and accurately.  This was a high quality item made of steel and aluminum designed for long-term continuous use.  The designs used by Addiator were successful enough in their own right that the name “Addiator” came to be used to refer to all calculators of this type, much in the same way you might use the name “Kleenex” to refer to a tissue or “Scotch” tape to refer to cellophane tape.

With the top section used for addition and the bottom portion for subtraction the Arithma was easy to use and intuitive.  On the top of the Arithma you’ll see a handle.  This was the reset mechanism which when pulled-out would reset all values to zero.

The Arithma measures 1.688″ W x 6.25″ H x 0.219″ D.  The one in my collection weighs 1.5 ounces with the stylus.  It should be noted though that on many of the advertisements it was mentioned that the Arithma weighed 3 ounces.  I’m unsure why there is a discrepancy, although my opinion is that in later versions more steel and less aluminum was used which increased the overall weight.

The Arithma was sold in the United States starting in 1957 and was advertised until 1973.  I do have independent data showing that as of 1975 over 2.5 million Arithmas had been sold in the U.S.  With electronic calculators becoming cheaper and more accessible about this same time it is unlikely the Arithma was sold after 1975.

The Arithma was manufactured in West Germany and imported into the United States by a company called Harrison Home Products Corp.  This company sold the Arithmas direct to retailers and also to consumers by mail order.  In 1968 the company changed names to Harrison-Hoge Industries Inc.  While the import company’s name will never be found on the Arithma itself, it will be found on both the box and the instructions.  If you have these you can date your Arithma to either pre-1968 or post-1968 by the company name used.

Carl Kubler wm

Carl Kubler, who was born January 13, 1875, started Addiator GmbH on February 13, 1920 in Berlin.  He was also the holder of both the German and U.S. patents for his adding machines.  Addiator ceased production in 1974 and went out of business officially in 1975.


newspaper ad from 1957


newspaper ad from 1968


newspaper ad from 1972

arithma bundle wm sm

Patent and Other Information:


  1. Editors (1923, October). A New Calculating Machine. Typewriter Topics, page 179
  2. Editors (1930, May). Addiator Ten Years Old. Typewriter Topics, page 164
  3. Read’s (1957, November). advertisement. The Bridgeport Post, page 23
  4. Harrison Home Products Corp. (1961, January). advertisement.Popular Science, page 41
  5. McDonald, Stingel & Bush Office Supply Catalog (1964), Saginaw, MI, page 433
  6. Madison House (1966, May). advertisement.  The Post Crescent, page 10
  7. Palm Co. (1968, December). advertisement. Colorado Springs Gazette-Telegraph, page 14
  8. Harrison-Hoge Industries Inc. (1972, September). advertisement. Progress Bulletin, page 18
  9. Harrison-Hoge Industries Inc. (1973, April). advertisement. Progress Bulletin, page 25
  10. F. Diestelkamp, (©2014), Addiator-Überblick. Retrieved April  18, 2016, from http://www.rechnerlexikon.de/artikel/Addiator-%DCberblick

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