Robert Pennington No. 1/430

An exceptional Regency small size 55-hour Observatory chronometer of probable Royal provenance. Circa 1801
No VAT will be charged on the hammer price, but VA… Read more George III was widely known to be fascinated with Science and all aspects of it, especially astronomy. He gathered together an auspicious collection of instruments the remaining core of which is formed by the apparatus and instruments supplied by George Adams. By the 1770s his collection was assembled at Kew Observatory and then subsequently the majority of the collection went to the newly founded King's College London where it was housed in a King George III Museum that opened in 1843. The Kew Observatory building was taken over by the newly founded British Association for the Advancement of Science and some telescopes and other astronomical apparatus were given to other observatories around Britain (notably Armagh Observatory). During the second half of the 19th Century King's College bought new items for teaching purposes and these have found their way into the collection. In 1927 most of the early material was taken to the Science Museum.
Robert Pennington No. 1/430 An exceptional Regency small size 55-hour Observatory chronometer of probable Royal provenance. Circa 1801

Details
Robert Pennington No. 1/430

An exceptional Regency small size 55-hour Observatory chronometer of probable Royal provenance. Circa 1801
THE MOVEMENT
Of fine execution, full plate construction, gilded
1. Train: with fusee, centre, third and fourth wheels with delicate hyperbolic crossings, motion wheels of brass, the arbors and pinions of polished steel, excepting the cannon pinion with 15-leaf brass pinion to the steel pipe with squared end, the balance and 'scape wheel jewelled with endstones to each and the fourth jewelled in pillar plate only. Count of 14,400 beating ½ seconds
2. Double mainspring assembly and fusee: fusee with Harrison's maintaining power and 11 turn cone. The sub-divided barrel assembly with double mainspring in two tiers with each spring (while attached to the common arbor) in its own barrel unit, the lower secured to the ratchet set up through the pillar plate, the upper fixed to the false barrel enclosing both units and carrying the fusee chain fixed at its outer end. Both springs dated K. Clark 1801
3. Escapement: Arnold-type spring detent, the gilt mounting block carrying separately planted steel detent proper and gold passing spring, each with facility for adjusting its depthing by means of an eccentric screw. Gold 'scape wheel of 16 teeth on the underside, umbrella wise. Compensated balance of Pennington's Y-C-C type, the three-armed solid brass rim with two bimetallic compensation affixes to its outside the timing adjustable by four quarter screws. Blued steel helical spring with adjustable collet at each end, having no terminal curves. 'Comma' shaped cock
THE DIAL
Of regulator format with annular minute ring, signed Pennington, London between the eccentric subsidiary rings calibrated for 24 hours above centred with crowned royal cypher GR and seconds below
THE DRUM
Of brass, containing the movement, glazed top and bottom, with vertical flange by '50' and attached hinged spring-loaded winding arm by '10'
THE BOX
Hexagonal, two tier, of Cuban mahogany with hinged brass observation cover signed Pennington London secured from the inside, and fixed brass plate on six cylindrical feet. Interior grooved for the drum flange, one exterior flat hollowed for the winding arm
Box: 135 mm. greater width, 60 mm. high
Movement: 88 mm. dial; 68 mm. pillar plate; 65 mm. top plate
Plates: 1.3 mm. thick; 23 mm. top plate to dial; 16.6 mm. plate separation
Drum: 95 mm. diam., 51 mm. high
Provenance
In view of the exceptional quality of this chronometer and its many refinements combined with King George III's cypher on the dial, it was almost certainly a Royal commission and may have been made for use in George III's observatory at Kew. It is possible that it was used in the Great Survey of England in the early 19th Century.

Christie's, London, 25 November, 1981, lot 210, The Property of a Lady Christie's, London, 12 June, 1996, lot 404, sold to the present owner.
Literature
Cedric Jagger, Royal Clocks, The British Monarchy and its Timekeepers, 1300-1900, Hale, 1983, p. 277, figs. 378 & 379
Dr. Vaudrey Mercer, The Penningtons and their Balances, in Antiquarian Horology, Vol. XII, No. 5 (Spring 1981), pp. 514-522, illus.
Cedric Jagger, Paul Philip Barraud (with Supplement), concerning the Mudge copies
Thomas Mudge, junior, A Description with Plates of the Timekeeper invented by the late Thomas Mudge, 1799, facsimile by Turner & Devereux, 1977
Special notice

No VAT will be charged on the hammer price, but VAT at 17.5% will be added to the buyer's premium which is invoiced on a VAT inclusive basis

Lot Essay

Robert Pennington, an eminent watchmaker, was working in London from about 1780 to his death in 1813. Pennington is believed to be the originator of the screw balance, of which this chronometer exhibits the earliest form. He is chiefly remembered as one of the finest horologists for his work with William Howells and others in producing at least 27 copies of Thomas Mudges's 'marine timekeepers' between 1794-1799, on behalf of the inventor's son and for whom he drew the excellent plates in A Description with Plates, published 1799.

It is significant, in the light of the only recently abandoned series of copies, that Pennington should have incorporated into his 1/430 certain features found in Mudge's timekeepers, but using the escapement (though with some modifications of his own) devised by Arnold, whom he considered a more capable horologist than Earnshaw (see Pennington's written submission concerning Arnold's and Earnshaw's Explanation to the Commission of Enquiry).

Unusually for an Arnold escapement, the discharging roller is beneath the impulse roller, an arrangment that is the opposite of Arnold's and more typical of an Earnshaw escapement.

The spring detent (see line drawing) and the mounting block assembly are very finely executed and probably unique in design. The detent is somewhat in the style of Breguet with a rectangular section cut out of the spring, between the root and the blade. Though the facility for depthing of the locking jewel and horn into the escapement for adjusting the 'lights' is not particularly unusual, the method of independently adjusting the depth of engagement of the passing spring and discharging jewel most certainly is.

With the exception of the balance cock endstone, the head of the securing screws for the jewel settings, or endstones where present, have a flat-filled edge to enable removal of the setting without completely undoing the screws.

The barrel assembly is identical to that fitted to Thomas Mudge Senior's No. 1, with the exception that in his chronometer the setting up of the mainsprings is by a worm and pinion, whereas Pennington employs a ratchet wheel and click. Two quite separate barrels operated within the outer brass casing or 'false barrel', and it is to this that the outer end of the fusee chain is hooked, in the usual manner. Each of these barrels has its own mainspring attached to the common arbor and these are wound in opposite directions - one clockwise and the other anti-clockwise - one being used to wind up the other. This arrangement gives the maximum output and the maximum number of turns of rotation of the barrel in the space available as it allows the full combined length of both mainsprings to be effective at the same time.
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