Weight-driven skeleton clock with experimental escapement
Record status
Individual type · partial
Period
1826
This skeleton clock features an experimental mechanism invented by James Wright and constructed by clockmaker George Andrew Jepson in 1826. It incorporates a silvered brass dial arrangement comprising four interlinked circles displaying running seconds, jumping hours through an aperture, and minutes indicated by blued steel hands.
The weight-driven movement utilizes a 360-toothed centre wheel and an experimental escapement with a wedge-shaped sapphire entry pallet and jewelled deadbeat-type exit pallet, transmitting impulse to a top-mounted gilt wood dumb-bell balance. The assembly is supported on a two-part mahogany case structured as a columnar pedestal on bun feet with an integrated mercury thermometer.
Evidence at a glance
- Linked sources
- 1
- Photograph views
- 1
- Catalogue references
- 0
Counts describe this entry’s documentation, not authenticity, rarity or completeness. Photographs may show one specimen; check each caption and licence.
Technical characteristics
- Type
- Skeleton clock
- Hour Display
- Weight-activated jumping hour system
- Total Height
- 2.05 metres (6 feet 9 inches)
- Dial Inscription
- Latin inscription recording the invention by James Wright and execution by Jepson in 1826
- Escapement Pallets
- Wedge-shaped sapphire entry pallet and jewelled deadbeat-type exit pallet
- Maker and Inventor
- Invented by James Wright, made by George Andrew Jepson
- Maker / attribution
- George Andrew Jepson (invented by James Wright)
Design
- Visible features
- • Full-height view of the skeleton clock movement mounted atop a tall mahogany column pedestal with bun feet. • Prominent circular skeleton dial rings and top-mounted dumbbell balance with outer timing discs. • Upper rectangular plinth section featuring carved foliate corner volutes beneath the movement.
- Dial Configuration
- The clock features a silvered brass dial arrangement comprising four interlinked circles, measuring between 2.5 and 8.5 inches in diameter. The display includes a seconds dial, a minutes ring, and a jumping-hour aperture, with time indicated by original blued steel hands. The seconds hand advances every two seconds. The third dial ring bears the Latin signature: "Inventum a Jacobo Wright quondam Coll: Hert et nuper Aul Mag: Oxon 1826 Jepson Fecit." The jumping-hour system is weight-activated; a three-wheeled pin begins to lift a weight on the half-hour, which is then released precisely on the hour to advance the display.
- Movement and Escapement
- The movement is driven by a lead weight on a double pulley connected to a barrel with 16 turns. Power is transmitted through three geared winding wheels to a 360-toothed centre wheel measuring 10 inches in diameter, which drives the minute hand and a 6-leaf pinion connected to a 30-toothed steel scape wheel. The escapement features a wedge-shaped sapphire entry pallet and a jewelled deadbeat-type exit pallet. These act on counter-balanced levers to provide impulse to a gilt-wood 'dumb bell' balance mounted above on a knife-edge suspension. The movement is housed in a brass frame with plates 5/8ths of an inch thick.
- Case and External Features
- The clock is mounted on a two-part mahogany case, consisting of an upper rectangular section supported by a circular column, socle, and square base on bun feet. The upper section features carved foliate corner volutes and a moulded cornice. The front of the case incorporates a 12-inch mercury thermometer with a silvered scale ranging from minus 10 to plus 110 degrees. The scale is hinged to provide access to the shuttered winding square. The total height of the assembly is 2.05 metres (6ft 9in), which includes the dome.
Identification
- Source note
- Facts transcribed from the linked source listing or collection record. Attribution and specifications are source-reported and have not been independently authenticated.
Catalogue references
No catalogue numbers recorded. Numbers are only published once transcribed from a verified edition of a standard catalogue — they are never inferred.
Research required
- Research required: Glazed hood described in the auction text is not present in this photograph.
- Research required: Fine dial engravings and the thermometer scale are not legible at this scale.