German silver watch with regulator dial and date Circa 1800

Gentleman’s Automatic pocket watch with cylinder escapement
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A very fine South German silver, rare keywind pocket watch with cylinder escapement and regulator dial and date in immaculate condition, circa 1800.
Full plate movement with unusual regulator setup, 1 barrel, five arm brass balance, plain baluster pillars, special form cylinder escapement. White enamel dial, black Arabic numerals, black outer minute track and inner hour track, and inner calendar markers. Polished open faced consular case. The case is stamped with JBP. Movement signed.
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Diameter: 58 mm
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Weight: 111 g
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Signed: Hahn Hofmechanicus Stuttgart
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Christoph Matthaeus Hahn was born on April 15, 1767, in Onstmettingen, in the region of Stuttgart. He was the son of Philipp Matthaeus Hahn and worked in his father’s workshop at first and then together with his brother Christian Gottfried Hahn. Together the brothers were “Hofmechanici” (makers of the court) in Stuttgart. 
Christoph is best known for his calculating machines, which he made with his father and later, after his father’s death, on his own. Hahn’s calculating machines are considered the predecessors of modern computers, and the name Hahn is found in every book about the history of computers. 
Besides making early computers, Christoph (as well as his father) produced a few calendar clocks and watches. Only a few are known to have survived, one in The British Museum and one in the museum of La Chaux-de-Fonds. The former Time Museum in Rockford, USA, owned another. In 1790 Christoph was awarded the title of Court Mechanician in Stuttgart. He died in Stuttgart on June 1, 1833. After his death, August Bacher took over Christoph Hahn’s workshop.