In the early 1890s, the German merchant Friedrich Wilhelm Küttner (1841-1920) from Burgk bei Potschappel (near Dresden) decided to invest a part of his money in creating a calculating machine. The device itself, based on the pin-wheel mechanism, known in Europe as Odhner’s wheel, was designed and manufactured by Woldemar Heinitz in his precision engineering workshop in Dresden (Heinitz and Küttner families were known to each other).
Woldemar Reinhold Heinitz (1874-1946) was a brilliant Dresdner engineer and manufacturer, who was a holder of numerous patents, primarily in the area of calculating machines and cash registers, and devoted most of his life to the production of mechanical calculators like Simplex, Duplex, Monopol and Comptator. Strangely, he became famous not with his masterly calculating machines, but with his collection of insects, which is now in the Chemnitz Natural History Museum.
Wilhelm Küttner received in 1894 a patent for his calculating machine (DE84269, 23.11.1894: Rechenmaschine mit Zwangsläufiger Bewegung der Registrirräder und des Tourenzählers). Later Küttner received Swiss (CH9450, 07.12.1894), French (FR243015, 20.11.1894), and US patents (US patent 650066, 23.01.1895, see the upper patent drawing).
The machine of Küttner (dimensions: 12 x 30 x 15 cm; weight: 7,8 kg) was the first pin-wheel machine that possessed tens-carry in the revolution counter, thus for the first time ensuring the appearance of the correct value in the revolution counter not only in ordinary but also in shortcut multiplications and divisions. The machine was manufactured under the names Simplex and Duplex for some time (1894-1902) by the company of Wilhelm Küttner and Woldemar Heinitz, Rechenmaschinenfabrik Heinitz & Küttner in Dresden.
Later on, Küttner sold the manufacturing rights to other companies, and the device was manufactured until 1904 under the name Monopol by the company Dresdner Kontrollkassen und Rechnungsfabrik in Dresden (under the direction of Heinitz) and then until 1914 by Schubert & Salzer in Chemnitz. There are also models with printing mechanisms, as well as with electrical operations.
The early examples based on Küttner’s machine differ from the later Monopoly machines in the position of the individual movements: In the early machines, the revolution counter and the result mechanism are at the front, both of which can be folded forward; behind it is the setting mechanism, which uses wheels with radially movable rungs. Despite the technical improvements, these very solidly built machines were unable to prevail against their competitors like Brunsviga.
