• CHF60 000 - 80 000
• -

C. Gilt brass pair case, custom made circa 1795, both polished. D. White enamel with Roman numerals and outer minute and seconds ring, custom made from the same period than the case. Gilt brass hands. M. Hinged gilt brass full plate, regular English calibre, fusee with chain and Harrison's maintaining power, the mainspring set-up is of the type typically associated with Emery. Unusual arrangement of the centre-seconds driving wheel so that the centre seconds hands can be stopped independently from the movement. The train count determine a balance frequency of 36, 000 beats per hour, extremely high frequency, probably unique for an 18^th century watch. Lever escapement of experimental type withighly polished steel wheel of "flat wheel cylinder" type, the lever with simple pointed pallets, one jewelled, the other steel. The banking is achieved with extensions to the pallet arms which stop on top of the escape wheel teeth. There is apparently no draw on the pallets. The fork and roller action simply consists of two independently friction-mounted "D" section pieces on the staff, rotatable so that the shake in the fork can be adjusted closely. Plain gilt brass three-arm balance with two sall steel poising screws eccentrically mounted, and inset in the rim. Blued steel balance spring with a long straight tail, controlled by curb pins to effect the corrections for temperature changes by means of "Chelsea Bun" type compensation, the curb is mounted on a sliding steel frame, which can be racked sideways to adjust the watch for meantime, by moving the curb pins along the tail of the balance spring. Diam. 54 mm.