The Centigraph adding machine was invented ca.1891 by Arthur Ewing Shattuck. It was produced first by The Centigraph Company of New York, New York and later by The American Adding Machine Company of Atlanta, Georgia. The Centigraph was nothing more than a simple adding machine and did not rise to the level of a true calculator.

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Have one for sale? Please email me at Antikey.Chop@gmail.com