The German mechanic, constructor and optician Anton (Antonius) Braun (see biography of Anton Braun) (1686-1728) from Möhringen (Baden-Württemberg, Germany), was appointed in 1724 as a mechanician and optician of the imperial court in Vienna, Austria. In the same 1724 he started to design a calculating machine for the purposes of the court. He finished his work in 1727, producing a calculating machine of a very good design and workmanship. When in 1727 he presented the machine to the Holy Roman Emperor Karl VI, he got into favor of the Emperor and was appointed as imperial instrument maker, and was granted with diamond chain, occupied with the portrait of the Emperor and a huge sum of money—10000 guilders.
The machine of Anton Braun is quite big—a finely decorated and looking like a renaissance table clock cylinder, made of steel, silver and brass with almost 40 cm diameter and 21 cm height.
The calculating machine of Anton Braun (© Deutsches Museum, Munich)
The calculating mechanism was based on the pin-wheel (or sprocket wheel), invented by Leibniz and Poleni, and described by Leupold. Obviously Braun was acquainted with the encyclopedia Theatrum Arithmetico–Geometricum of Leupold, where was described the machine of Poleni. But in contrast to the machine of Poleni, the Braun's was a smaller, more easy for use and perfectly manufactured device, which actually is considered as the first easy to operate mechanical calculating machine.
The first calculating machine of Anton Braun from 1727 (© Technischen Museum, Wien)
There is another calculating machine of Braun, still preserved in Technischen Museum in Wien (see the upper images), which had an engraved dedication to the Kaiser Karl VI and also the self-conscious signature "Antonius Braun S.C.M. Opticus et mathematicus", with the year of completion in 1727. There is information however, that this machine is not the original one, made by Anton Braun in 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.
It seems Anton Braun actually designed two quite different internally calculating machines. Besides the device, presented to the Emperor, he designed also another much smaller calculating machine, similar in appearance to the first, but its calculating mechanism is almost identical to the Leupold's machine and is based on a ratchet-wheel. This machine probably was only begun in the workshop of Braun, but after his death (he died on 20 April 1728 from the infection of the lungs) it was finished as late as in 1736 by his son and by the famous french mechanician Phillippe Vayringe (1684-1746), who was hired by the Emperor to fix the machine, kept in his collection. 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 (see the first photo of the article and the photos below).
The calculating machine of Leupold-Braun-Vayringe from 1736 (© Deutsches Museum, Munich)
The machine 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.
There are also several modern replicas of the machine, one of them is very beautiful with its transparent glass lid (see the photo below).
A copy of the calculating machine of Braun-Vayringe from 1736 with a glass lid