A fine and rare late 18th century mahogany month duration floorstanding regulator of exceptional provenance
Arnold, London, Number 33
Constructed throughout out of dense mahogany, the backboard measuring just under 2 inches in thickness, the seatboard measuring a full 2 inches in depth. The hood with moulded concave cornice over a flat-fronted door with brass lock, the sides solid and relieved by an applied moulded rectangle on each side in lieu of sight windows, the 30 inch trunk door of good figure within a simply moulded edge, and substantial lock in the usual position, the base panel also set with an applied rectangle, and set on original double skirted plinth. The case further mounted with a substantial iron strap measuring 1/2 an inch thick, 2 inches wide and 16 inches long at its shaped tips with screw adjustment, secured with seven large countersunk screws, set into the body of the backboard approximately two thirds of the way up to facilitate absolutely precise levelling
The 12 inch square silvered one-piece dial with outer Arabic minute track with original blued steel hand, counter-weighted via a triangular brass weight set on the arbor behind the dial, enclosed by a single line border, the centre set with a large subsidiary dial for running seconds, again with original hand and marked in Arabic five minute divisions and with twelve bold Observatory marks, the hours shown in Roman numerals running from I to XXIV through a downward-curving aperture set immediately below the centre, signed in the lower half of the dial in elaborate copperplate script "Arnold, London, No.33". Winding to the left of centre and attached to the movement via four turned brass dial feet secured to the frontplate by three screws into substantial collets.
The weight driven movement with very substantial brass plates one quarter of an inch thick and measuring 10 inches by 7 inches, with angled upper corners, united by six heavy tapering cannon barrel pillars screwed to the frontplate with heavy turned brass collets, with Harrison's maintaining power, the barrel arbor, great wheel, hour wheel and centre wheel all set in adjustable endstops, the third wheel and 'scape wheel arbors set in triple-screwed jewelled chatons, each wheel of six crossings and with screwed collets and twelve-leaf pinions, the deadbeat escapement 'scape wheel particularly well made with large polished steel anchor spanning 11 teeth and inset with jewelled faces, to a long steel crutch with twin-screw micrometer beat adjustment, the uppermost section of the fork overlaid with two strips of pink gold slightly wider than the steel section below so that the pendulum rod is in contact with the gold strip rather than the steel body of the crutch. The pendulum suspended from a heavy triangular brass bracket let into the body of the backboard, generally of massive construction and consisting of a central steel rod flanked by a pair each of zinc and steel rods, all contained within five heavy brass blocks at the top, bottom and mid-point, terminating in a brass bob of 7.25 inches diameter and flattened oval section, the central portion left deliberately open so as to expose the bimtellic terminal to the air, with engraved silvered brass regulation nut and pointed tip 193cms (6ft 4ins) high.
- Please note the estimate should read £50,000-£70,000