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Centrigraph Adding Machine

As a typewriter enthusiast, I find it very interesting that one of those earliest historical mentions of a Centigraph was alongside Williams typewriters. In an October 14, 1893 issue of The Phonetic Journal, a U.K. periodical, it states that the Centigraph was distributed and exhibited with several Williams products by and outfit from Plymouth, England.

Centrigraph Adding Machine Patent
Centrigraph Adding Machine
Centrigraph Adding Machine

It is difficult to find any evidence that suggests if the adding machine was marketed, or even produced, by The Centigraph Company after 1893. We do know that sometime between then and before 1902 the rights to produce it were sold to the American Adding Machine Company (AAMC) of Atlanta, Georgia. Why 1902? Because that is when The Cotton States & Belting Supply Company (also from Atlanta) was reported to have an interest in buying the AAMC, specifically for the Centigraph business. The purchase never took place because, in 1903, ads for the Centigraph began running again but with the AAMC's name on them.

Write-ups proclaimed that the Centigraph differed from others adding machines because it"...adds a single column at a time and it has only five keys. These keys represent the numbers 1, 2, 3, 4, 5, and the numbers 6, 7, 8, 9 are obtained by simultaneously depressing the pairs of keys 5-1, 5-2, 5-3 and 5-4 respectively. The keys 1, 2, 3 and 4 actuate pawls on a disc, which carries 100 notches in its circumference, and the 5 key actuates a pawl on a parallel and similar disc with 20 notches in its circumference. The two discs travel round in opposite directions. The discs are mounted on the same axis, and are connected together solely by a coiled spring round that axis. The 100-notch disc carries the numbers 1-99 and the total added together appears through a square hole in the 20-notch disc There is a spiral groove in the 100-notch disc, in which travels a pin carried at the end of a pointer pivoted to the 20-notch disc. This pointer indicates the hundreds up to 500. A milled handle attached to the center of the 20-notch disc is used for bringing the disc to zero, and it winds up the spring in the operation."

I'm VERY interested in acquiring these and other interesting adding machines. If you have one please email me at

Other interesting calculators here.


1891 - 1903

The Centigraph Co.

New York, New York, U.S.

The American Adding Machine Co.

Atlanta, Georgia. U.S.


The Centigraph is an adding machine that dates to as early as 1880 when inventor Arthur Ewing Shattuck (1854 - 193?) first filed for its patent. He eventually received that patent (no.453,778) an astonishing 11 years later, in 1891. By then, the Centigraph Company had already been formed, during the previous year of 1890. The company was located at 34 Maiden Lane in New York City (now demolished and a new structure sits in its place) which was once the home of toy importers Purdy and Robbins. It wasn't until 1893 that any serious reviews or advertisements began populating various periodicals for the Centigraph.

Arthur Ewing Shattuck
Centrigraph Adding Machine Ad
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