Editing Mechanical calculator (section)

===Prototypes and limited runs===
[[File:Rechenmaschine.jpg|thumb|A mechanical calculator from Anton Braun, dated 1727]]
* In 1709, Italian [[Giovanni Poleni]] was the first to build a calculator that could multiply automatically. It used a pinwheel design, was the first operational ''calculating clock'' and was made of wood;<ref>[http://www.museoscienza.org/approfondimenti/documenti/macchina_poleni/replica.asp Copy of Poleni's machine] (it) Museo Nazionale della Scienza e della Tecnologia Leonardo Da Vinci. Retrieved 4 October 2010</ref> he destroyed it after hearing that Antonius Braun had received 10,000 [[Rhenish guilder|Gulden]]s for dedicating a pinwheel machine of his own design to the [[Charles VI, Holy Roman Emperor|Holy Roman Emperor Charles VI]] in [[Vienna]].<ref>[[#MARG|Jean Marguin, p. 93-94 (1994)]]</ref>
* In 1725, the [[French Academy of Sciences]] certified a calculating machine derived from Pascal's calculator designed by Lépine, a French craftsman. The machine was a bridge in between Pascal's calculator and a calculating clock. The carry transmissions were performed simultaneously, like in a calculating clock, and therefore "the machine must have jammed beyond a few simultaneous carry transmissions".<ref>translated from the French: "De plus le report ne s'effectuant pas en cascade, la machine devait se bloquer au-delà de quelques reports simultanés", [[#MARG|Jean Marguin]], p.78 (1994)</ref>
* In 1727, German [[Antonius Braun|Anton Braun]] presented the first fully functional four-operation machine to Emperor Charles VI in Vienna. It was cylindrical in shape and was made of steel, silver and brass; it was finely decorated and looked like a renaissance table clock. His dedication to the emperor engraved on the top of the machine also reads "...to make easy to ignorant people, addition, subtraction, multiplication and even division".<ref>[[#MARG|Jean Marguin, p.94-96 (1994)]]</ref> 
* In 1730, the French Academy of Sciences certified three machines designed by [[Hillerin de Boistissandeau]]. The first one used a single-tooth carry mechanism which, according to Boistissandeau, wouldn't work properly if a carry had to be moved more than two places; the two other machines used springs that were gradually armed until they released their energy when a carry had to be moved forward. It was similar to Pascal's calculator but instead of using the energy of gravity Boistissandeau used the energy stored into the springs.<ref>[[#MARG, Jean Marguin]], pages 80–81 (1994)</ref>
* In 1770, [[Philipp Matthäus Hahn]], a German pastor, built two circular calculating machines based on Leibniz' cylinders.<ref>[[#MARGIN|Marguin, p.83 (1994)]]</ref><ref>[https://web.archive.org/web/20050409124858/http://www-03.ibm.com/ibm/history/exhibits/attic/attic_137.html Picture of Hahn's Calculator] IBM Collection of mechanical calculators</ref> [[J. C. Schuster]], Hahn's brother-in-law, built a few machines of Hahn's design into the early 19th century.<ref>[[#MARGIN|Jean Marguin, pages 84–86 (1994)]]</ref>
* In 1775, [[Charles Stanhope, 3rd Earl Stanhope|Lord Stanhope]] of the United Kingdom designed a pinwheel machine. It was set in a rectangular box with a handle on the side. He also designed a machine using [[Leibniz wheel]]s in 1777.<ref>[[#FELT|Door E. Felt, p.15-16 (1916)]]</ref> "In 1777 Stanhope produced the ''Logic Demonstrator'', a machine designed to solve problems in formal logic. This device marked the beginning of a new approach to the solution of logical problems by mechanical methods."<ref name="Chronicle, p. 12"/>
* In 1784, German [[J. H. Müller|Johann-Helfrich Müller]] built a machine very similar to Hahn's machine.<ref>{{cite web|url=http://cnum.cnam.fr/CGI/fpage.cgi?8KU54-2.5/253/150/369/363/369|title=CNUM – 8KU54-2.5 : p.249 – im.253|website=cnum.cnam.fr}}</ref>