Swiss lever watch with one minute tourbillon regulator Circa 1880

Silver open faced tourbillon watch
–
A fine and rare silver open faced pocket watch with one minute tourbillon made in Switzerland, circa 1880. A polished case and hinged silver cuvette with apertures for winding and hand setting. White enamel dial with radial Roman hour numerals, an outer minute track, subsidiary seconds at 6 o’clock and blued steel Breguet hands. Matte gilt movement with a circular skeletonized plate securing the going barrel, center wheel and tourbillon carriage, jewelled lateral lever escapement, monometallic balance, flat balance spring, steel and brass tourbillon carriage rotating once per minute and the seconds hand driven by a wheel mounted on the lower tourbillon pivot mounted beneath a separate plate on the dial plate.
–
Diameter: 58.5 mm
–
Signed: No name
–
A tourbillon ( (whirlwind in English)) is a mechanism to reduce the influence of gravity on the movement of a mechanical timepiece in order to increase accuracy. The Swiss-French watchmaker Abraham Louis Breguet invented the tourbillon in 1795 and received a patent for it on June 26, 1801. In a tourbillon, the escapement and balance wheel are mounted in a rotating cage to eliminate balance errors, creating a uniform weight.