Description: Brass movement calibre for a pocket chronometer (45mm diameter), bilaterally engraved (left: front, right: rear) wheel positions and pierced pinion holes, engraved bridge positions, no indication of teeth number. Later ‘garde temps’ style with two barrels wound by a common square. Parachute suspension for the balance pivots, Earnshaw spring detent escapement. The dial would have been silvered and of regulator type, with an excentric minute hand, a quite big second work at 12 and a smaller hour work at 6. Also the dial prototype is engraved overlapping the front part: winding indication top left, equation of time top right, seconds at 6.
Provenance: Ex. George Brown, thence by decent
Additional Info:
No watch with this exact movement is known, but it seems to be a development close to piece No. 3787, sold 1823. Latter watch is slightly bigger, but retaines all features and proportions shown in the calibre.
Ref.: G. Daniels, ‘The Elsom II’, 1974
Antiquarian Horology 