Anton Braun

When in 1724 the German mechanic Anton Braun (1686-1728) got an appointment as a mechanic and optician of the imperial court in Vienna, Austria, he started to design a calculating machine for the purposes of the court. Braun finished his work in 1727, producing a calculating machine of very good design and workmanship. When in the same year he presented the machine to the Holy Roman Emperor Karl VI, he was so impressed, that later appointed him as Imperial instrument maker, and granted him a diamond chain (with the portrait of the Emperor) and a huge sum of money—10000 guilders.

It seems at the same time when Braun designed and made the calculator, and presented it to the Emperor (we will call it the first machine of Braun), he devised a similar device, but with a different calculating mechanism (let’s call it the second machine of Braun). Obviously, Braun knew the machines of previous inventors, like Poleni (the first machine’s calculating mechanism is based on the pin-wheel of Leibniz and Poleni), and Leupold (the second machine’s calculating mechanism is based on the switching latch of Leupold, and the appearance of both machines is similar to Leupold’s device.)

There is an interesting story, connected with the first machine of Braun. One of the biographers of Poleni, the Frenchman Jean de Fouchy Pajil Grandjean, claims in his 1762 book “Eloge de Jean POLENI, Marquis du St. Empire, (né 1683 mort 1761)”, that …having heard that Mr. Brawn, a famous mechanic in Vienna, presented a similar machine to the Emperor, Poleni destroyed his machine and no more wanted to rebuild it. Despite the fact, that Fouchy was in strict contact with Poleni (when alive) and knew him personally, this story is quite questionable, not only because it is not compatible with the gentle character of Poleni. It is possible Braun to had gotten information about Poleni’s machine (Braun worked under the supervision of the imperial engineer Johann Jacob Marinoni, who was in correspondence with Poleni and perhaps visited him in Venice), and so decided to use the idea of Poleni in his construction, the history of inventions is full of cases like that. In fact, if Poleni didn’t manage for almost 20 years to manufacture and demonstrate a working copy of his machine, obviously he was not interested in this device at all and fully deserved to be outrun by others.

The first calculating machine of Anton Braun is quite big (almost 40 cm diameter and over 20 cm height) and a fancy device, finely decorated and looking like a Renaissance table clock cylinder, made of gold, steel, silver, and brass.

The example of the first machine, which survived to our time (see the upper image), has an engraved dedication (in Latin) to the Kaiser Karl VI and also the signature “Antonius Braun S.C.M. Opticus et mathematicus”, with the year of completion 1727. The whole inscription is: MACHINA ARITHMETICA PER QUAM ADDITIO, SUBSTRACTIO, MULTIPLICATIO ET DIVISIO ETIAM AB IGNARIS ARITHMETICES FACILLIME PERAGUNTUR. AUGUSTISSIMO ATQUE INVICTISSIMO ROMANORUM IMPERATORI CARLO SEXTO, GERMANIAE, HISPANIAE, HUNGARIAE, BOHEMIAE REGI, ARCHIDUCI AUSTRIAE MACHINAM HANC ARITHMETIC AMIN PERPETUAE GRATITUDINIS TESSERAM SUBJECTISSIME DICAT, DEDICAT CONSECRATQUE HUMILLIMUS INVENTOR ANTONIUS BRAUN S. C. M. OPTICUS ET MATHEMATICUS. 1727.

The example on the image is not the original one, made by Anton Braun in the 1720s, but a copy, made in 1766 by his son—Anton Braun the Younger (1708-1776), who just like his father was a skillful optician and watchmaker (the case was made by famous Munich sculptor Johann Baptist Straub).

The calculating mechanism was based on the pin-wheel (or the sprocket wheel), invented by Leibniz and Poleni. The machine’s six-place setting mechanism is in the form of six circular segments arranged in a circle on the top, with nine sliders each (for digits 1 to 9), which move the relevant pins radially outwards on the pin-wheels below. Turning the crank adds the entered number to the result mechanism (12-digits with complementary numbers shown), and the result is shown in the windows along the periphery of the cover (the silver-plated part). The setting mechanism can be rotated with respect to the result mechanism so that both multiplication and division are possible. The machine also featured a single-digit revolution counter.

The second calculating machine of Anton Braun (see the image below) is a much smaller device, similar in appearance to the first machine (round shape, crank in the middle, concentrically arranged numerical windows, and magnificent decorations), but its calculating mechanism is almost identical to the Leupold’s machine and it is based on a ratchet-wheel. This machine probably was only begun in the workshop of Braun, but after his early death in 1728, it was finished as late as 1736 by his son and by the famous French mechanic Phillippe Vayringe (1684-1746), who was hired by the Emperor to fix the machines, kept in his collection. The only surviving example of the machine (on its lid is engraved Braun invenit, Vayringae fecit) (Invented by Braun, manufactured by Vayringe) is now in the exposition of Deutsches Museum, Munich.

The second calculating machine of Braun is commonly named Leupold-Braun-Vayringe machine, due to the fact, that the idea of the calculating mechanism was proposed by Leupold, the construction was made by Braun, while the actual manufacturing was made by Vayringe. It is believed that Braun had already gotten to know and realized Leupold’s construction in detail before his volume Theatrum arithmetico-geometricum was published in 1727. Leupold himself reported that he had been dealing with calculating machines “for more than 20 years”, that he “had released four to five types” and that he “could show their workings to different friends”.

The machine featured a single central so-called adapting segment, which allowed the number of special, complicated parts to be greatly reduced. Below the setting mechanism is placed a set of vertical cylinders, each with nine rods of different lengths rising from its top. For example, if digit nine was entered, the shortest rod was rotated to the outside, and then one full turn of the crank turned the central adapting segment once around the central axle. It consisted of a disc with various steps as well as a segment with nine cogs. When it was turned once round, it passed the setting cylinders, on each of which a certain rod pushed the corresponding step outwards, whereupon the cog-segment of the adapting segment engaged a cog-wheel of the result mechanism and thus rotated the numbered disc to the correct digit in the corresponding window. Thus, the smaller the entered digit was, the later the adapting segment engaged, and fewer cogs were moved. Multiplication was done by repeated revolutions of the crank, as a place-shift mechanism enables multiplying with multi-digit multipliers. Subtraction (and division) were done using the 9-complements of digits.

Even though the tens-carry mechanism of the machine did not function properly in every place, the idea of a central adapting segment was a great innovation that found extensive use in several brilliant mechanical calculators some 200 years later on, like the magnificent Curta of Herzstark, even though it used a stepped drum as the central element.

The collection of Deutsches Museum, Munich (the world’s largest museum of science and technology), contains not only the original of Leupold-Braun-Vayringe machine but also a very beautiful modern replica with a transparent glass lid (see the nearby photo).

Biography of Anton Braun

Anton (spelled also Antoni and Antonius) Braun was born on 22 October 1686, in Möhringen an der Donau (bei Tuttlingen), a small town on the upper Danube, in Baden-Württemberg, Germany, in an old Bürger family, mentioned to live in Möhringen as long ago as in 1491. Anton was the first child from the second marriage of Hans Jacobus Braun (born 25 July 1651) and his wife Franziska Riestler (Hans Jacobus Braun had three daughters and two sons from his first marriage). Anton Braun had a younger brother, Johann Georg (b. 27 May 1688), who also became an optician and instrument maker, but could never reach the technical brilliance of his elder brother.

Hans Jacobus Braun used to work as a mechanic and watchmaker, so obviously, Anton learned the basics of mechanics in his parental home.

Anton Braun probably married young in his hometown, because in 1708 was born his son, Anton Braun Jr. (der Jüngere) (1708-23.10.1776), who also became a skillful instrument maker, optician, and watchmaker as his father, and made the copy of one of his calculating machines, still preserved in Technischen Museum, Wien.

At some point, Braun left his hometown to go to Vienna, most probably to study at the University of Vienna. There on 19 April 1712, Braun, designated as “University optician and mathematician” married in Cathedral St. Stephan, to Maria Magdalena Steinin (the daughter of Georg Stein, the postmaster at Ettlingen in Swabia, and his wife Maria Eva).

Braun probably left Vienna soon after his marriage, because he established mechanical workshops in Prague and Milan in the following years. During this period, Braun became one of the most prominent instrument makers of his time and was highly appreciated by the Imperial Engineer and professor at the University of Vienna—Johann Jakob Marinoni (see the nearby portrait). Braun was warmly recommended by Marinoni and worked for him in the years 1719-1722 as a surveyor in cadastral surveying in the duchy of Milan.

Anton Braun returned to Vienna in 1723, and the next year he was appointed to the prestigious position of Kammeropticus und Mathematicus at the Austrian court, due to his outstanding precision mechanical, and mathematical skills. Three years later, he sat down as a candidate for the post of Imperial instrument maker (Kaiserlicher Compaß- und Instrumentenmacher). And he won (there were four candidates), presenting to the Emperor his advanced calculating machine, which he constructed in 1724 and which was already in use at the imperial court.

Braun apparently got in favor of the Holy Roman Emperor Karl VI, because he was not only appointed as an imperial instrument maker but was also granted a 12-diamond chain (value of 500 guilders), occupied with the portrait of the Emperor (kept now in the Museum in Rathaus Möhringen) and a huge sum of money—10000 guilders. The 10000 Gulden were never paid out, however, because of war-related expenditures and financial difficulties of the Viennese Court under Empress Maria Theresia, the daughter of Karl VI. Nevertheless, Braun bequeathed half of his assets to his hometown, so 6000 guilders were used for charity and the construction of a hospital.

A circular sundial made by Anton Braun in 1719 is kept now in the collection of the Adler Planetarium in Chicago.

Unfortunately, Braun’s tireless zeal and restless activity used up his physical powers early, and he died too young (41 years old) from a long-running lung disease, on 20 April 1728, in Vienna. His brother Johann Georg also got the support of Marinoni and succeeded Anton’s position as Kaiserlicher Optikus.