Swiss nickel open faced tourbillon pocket watch Circa 1910

Nickel poor man’s lever watch with tourbillon by Mobilis
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A rare Swiss nickel open faced keyless winding tourbillon pocket watch with a matching chain, a so-called poor man’s tourbillon, circa 1910. Movement after patent No. 30754 with a straight line lever escapement.
Gilt, textured dial, small, silvered eccentric time indication in the upper half with radial Roman hour numerals, outer minute dots and cathedral hands, an aperture to view the visible tourbillon with a decoratively engraved balance bridge. A plain case.
Movement signed and numbered.
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Diameter: 52 mm
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Weight: 105 g
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Signed: Mobilis
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Mobilis tourbillon 
At the beginning of the 20th century, Paul Loichot, from Charquemont in Doubs, France, invented and patented an interesting tourbillon design in Switzerland (Swiss Patent No. 30754 from June 11th, 1904). He inverted the movement, allowing the carriage to be seen through the dial and placed the escapement in a straight line with a lever opening for the carriage arbour.

Courvoisier Frères, La Chaux-de-Fonds, registered the brand name Mobilis, on July 4th, 1905 (Swiss mark No. 19062).