English silver watch with chronograph stopwatch Circa 1890

Silver lever pocket watch
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English silver and pink gold keyless pocket watch, circa 1890. With a chronograph stopwatch, capable of measuring intervals as short as 1/16 of a second, made to the design of William’s. The case with Chester hallmarks for 1890-91. Master mark JE, polished case, pink gold hinges, stop-slide, and hand-setting nib. Hinged silver cuvette. Off white enamel dial, radial Roman numerals, outer minute and seconds divisions, outermost second divisions calibrated to 960 units, subsidiary sunk 1/16th seconds dial and gold spade hands. A frosted gilt 3/4-plate movement, 17 jewels, some in screwed chatons, fast beating 60° lateral counterpoised lever escapement, three arm gold balance, flat balance spring, index regulator. Dial and movement signed.
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Diameter: 58 mm
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Signed: William Williams  Bury
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The dial is slightly scratched.
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The Swiss patent for the Montre Mystérieuse was published on January 24th, 1889. The description with diagrams describes this model as a watch where the movement is invisible and the watch’s body is composed of transparent glass. The hour hand is driven by one glass rotated by teeth around its perimeter, and the minute hand is by a tiny wheel at the back of the hands engaging with the hour wheel.