| Thomas
"Arithmometer" 1820 |
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| "The honor of first establishing the manufacture of calculating
machines as an industry goes to Charles Xavier Thomas of Colmar, France, or Thomas de
Colmar, as he is more commonly known. Like Hahn, Thomas used the stepped cylinder invented
by Leibniz as his digital-value actuator." George C. Chase, "History of Mechanical Computing Machinery." Annals of the History of Computing, Vol. 2, No. 3, July 1980. |
| For information on Thomas de Colmar patents and a picture of his Piano Arithmometer click here. |
Photo Source: The Popular-Science Museum in The Hague, Netherlands |