Editing Mechanical calculator (section)

===Overview===
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[[Luigi Torchi (inventor)| Luigi Torchi]] invented the first direct multiplication machine in 1834.<ref>{{cite web|url=http://history-computer.com/MechanicalCalculators/19thCentury/Torchi.html|title=History of Computers and Computing, Mechanical calculators, 19th century, Luiggi Torchi|website=history-computer.com|date=4 January 2021 }}</ref> This was also the second key-driven machine in the world, following that of [[James White (inventor)|James White]] (1822).<ref name="Roegel">{{cite journal|doi=10.1109/MAHC.2016.46|title=Before Torchi and Schwilgué, There Was White|year=2016|last1=Roegel|first1=Denis|journal=IEEE Annals of the History of Computing|volume=38|issue=4|pages=92–93|s2cid=28873771 }}</ref>

The mechanical calculator industry started in 1851 [[Thomas de Colmar]] released his simplified [[Arithmometer|Arithmomètre]], which was the first machine that could be used daily in an office environment.

For 40 years,<ref>This is one third of the 120 years that this industry lasted</ref> the arithmometer was the only mechanical calculator available for sale and was sold all over the world. By 1890, about 2,500 arithmometers had been sold<ref>{{cite web|url=http://www.arithmometre.org/NumerosSerie/PageNumerosSeriePayen.html|title=www.arithmometre.org|website=arithmometre.org}}</ref> plus a few hundreds more from two licensed arithmometer clone makers (Burkhardt, Germany, 1878 and Layton, UK, 1883). Felt and Tarrant, the only other competitor in true commercial production, had sold 100 comptometers in three years.<ref>{{cite book|last=Felt|first=Dorr E.|title=Mechanical arithmetic, or The history of the counting machine|publisher=Washington Institute|location=Chicago|page=4|year=1916|url=https://archive.org/details/mechanicalarithm00feltrich}}</ref>

The 19th century also saw the designs of Charles Babbage calculating machines, first with his [[difference engine]], started in 1822, which was the first automatic calculator since it continuously used the results of the previous operation for the next one, and second with his [[analytical engine]], which was the first programmable calculator, using Jacquard's cards to read program and data, that he started in 1834, and which gave the blueprint of the [[mainframe computers]] built in the middle of the 20th century.<ref name=BABBAGE>"The calculating engines of English mathematician Charles Babbage (1791–1871) are among the most celebrated icons in the prehistory of computing. Babbage's Difference Engine No.1 was the first successful automatic calculator and remains one of the finest examples of precision engineering of the time. Babbage is sometimes referred to as "father of computing." The International Charles Babbage Society (later the Charles Babbage Institute) took his name to honor his intellectual contributions and their relation to modern computers." [http://www.cbi.umn.edu/about/babbage.html Charles Babbage Institute] (page. Retrieved 1 February 2012).</ref>
[[Image:DesktopMechanicalCalculators inProduction intheXIXCentury.svg|thumbnail|upright=2.6|center|<div align="center">Desktop Mechanical Calculators in production during the 19th century</div>]]