A unique and quite remarkable early 19th century weight driven skeleton clock with complex experimental escapement
Invented by James Wright, made for him by the clockmaker George Andrew Jepson in 1826
The silvered brass dial consisting of four interlinked circles, measuring between 2.5 and 8.5 inches in diameter; the smallest showing running seconds and engraved in Arabic fives around an engraved band, the second partially etched in black with an open centre revealing the hour, the third with banded decoration to its periphery and carrying the full signature
a Jacobo Wright quondam Coll:
Hert et nuper Aul Mag: Oxon
and the largest in the form of an open centred ring showing minutes, again, marked in Arabic fives with an engraved band to the inner edge, with original blued steel hands. The seconds are shown on the uppermost dial via a running hand advancing every two seconds. The minutes are shown on the largest dial and are driven directly from the centre wheel. The hours are displayed through an aperture and are shown on a weight-activated jumping hour system; on the half hour, a three-wheeled pin begins to lift a weight set below the hour dial, as the minute hand revolves, the weight is lifted over a pulley so that precisely on the hour, the pin is released and the hour jumps forward.
The lead weight fixed on a double pulley to give longer duration and driving a barrel of 16 turns, wound via a protected winding square accessible only on pulling forward the hinged thermometer plate, to a series of three geared winding wheels; the great wheel driving a 16 leaf pinion to a 360-toothed centre wheel measuring 10 inches in diameter with six finely shaped tapered crossings, directly driving the minute hand; the centre wheel also drives a 6 leaf pinion linked to a substantial, solid steel 30-toothed 'scape wheel. The scape wheel is controlled by a wedge shaped sapphire entry pallet acting in conjunction with a jewelled
deadbeat-type exit pallet. These pallets are set onto an ingenious system of counter-balanced pivotted levers that transfer impulse to the gilt wood 'dumb bell' balance mounted above, set on a knife edge suspension, and terminating at each end with a turned brass timing disc, japanned black and offering some form of micrometer regulation via a pair of endless screws.
All of the above is set within a heavy brass frame, the plates measuring 5/8ths of an inch thick and cast in the form of a stylised hour glass united by four plain turned pillars
All protected from the elements and probing fingers by a rectangular framed glazed hood that.
In two parts, the upper section a rectangular-section mahongany plinth that carries the movement and dome, set with a moulded cornice over a recessed centre panel and crisply carved foliate volutes to each corner, applied to the front with a 12 inch long mercury thermometer with large bulb and engraved silvered scale measuring from minus 10 to plus 110 degrees, the brass scale itself hinged at the right hand side and when opened will display the shuttered winding square for the winding arbour; this plinth is further set on a circular-section column terminating in a short socle and square base on squat bun feet
Total height including the dome is 2.05m (6ft 9in) high. Movement frame height 27cm (10.5in) high.