Very early machine for adding and subtracting numbers from 0-100 in the shape of an astrolabe. This antique adding machine - signed “Pierre Fardoil à Paris” is hand-crafted in steel and brass, measures 5-1/2 inches in height and is in perfect working condition.
There are less than ten other models of calculators known which were invented or made before circa 1700.
![Pierre-Fardoil-Calculator-and-Pocket-Watch-c.1700](https://www.rarestfinds.com/rfp/07647-01L.JPG)
Fardoil’s contribution to the development of mechanical calculating devices is the introduction of his mechanism which enables the operator to read the result without counting the dividing marks on a circular scale of a disc shaped antique adding machine. Fardoil achieved this improvement by utilizing a planetary gear turning two round scales underneath two stationary hands ten times over the entire range of the calculator. The two scales show the numbers from 0-9 for additions and for subtractions respectively. This simple use of a planetary gear enabled Fardoil to provide a read-out in the range of 0-100 without the need of a carry-over from 9 to 10, 20, 30, etc.
Unlike the very early calculators by Schickard, Leibniz, Pascal, Grillet, and others, Fardoil's antique calculator was a true “pocket calculator” as it is flat and would fit in any pocket.
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Posted on 11 Feb 2020, 02:31 - Category: Office, Banking
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