Fine and extremely rare silver pair case spring detent pocket chronometer by
Thomas Earnshaw, London, circa 1813.
White enamel dial with black numerals and gold hands.
10 jewel fusee movement with engraved cock with diamond cap, "Z" freesprung balance with
trapezoidal weights, gold timing screws and helical hairspring.
The inner case with some small dents.
Thomas Earnshaw was one of England's most illustrious makers. He invented the
spring detent chronometer escapement in late 1780 and his design has been
employed in the vast majority of marine chronometers made since then.
The inner case is hallmarked 1813. The outer case is hallmarked 1848 which
indicates that it is either a replacement or a purpose-made case.
