Robert Pennington, London

• Movement: gilded movement, Arnold type detent, gold escape wheel, 'YCC'  type one balance with three arms and two semi-circular bi-metallic affixes, helical spring, plain balance cock with diamond endstone, keyless winding work visible to the backplate, fusee and chain • movement signed Pennington, London 1/430
• Dial: silvered regulator type dial, 24-hour dial above with Arabic numerals, Crown and Royal Cipher within, large subsidiary seconds dial, outer Arabic minute track, blued steel hands • dial signed
• Case: plain brass case, outer original mahogany brass mounted deck case, the heavy brass lid engraved Pennington London, lock to the front, side with recess for winding, brass base with short cylindrical feet, with key to deck case

Christie’s London, 12^th June 1996, lot 404

Terence Camerer Cuss, The English Watch 1585-1970, 2009, pp. 326-327, pl. 206

Movement running at time of cataloguing and appears clean and in good order. The dial with some light wear he silvered finish and a couple of small stains. Spotting and wear to the finish of the brass case as to be expected. Brass and mahogany case with an attractive patina and old marks, scuffs and scratches as to be expected.
"In response to your inquiry, we are pleased to provide you with a general report of the condition of the property described above. All dimensions in catalogue descriptions are approximate. Condition reports may not specify mechanical replacements or imperfections to the movement, case, dial, pendulum, separate base(s) or dome. Watches in water-resistant cases have been opened to examine movements but no warranties are made that the watches are currently water-resistant. Please note that we do not guarantee the authenticity of any individual component parts, such as wheels, hands, crowns, crystals, screws, bracelets and leather bands, since subsequent repairs and restoration work may have resulted in the replacement of original parts. Since we are not professional conservators or restorers, we urge you to consult with a restorer or conservator of your choice who will be better able to provide a detailed, professional report. Prospective buyers should inspect each lot to satisfy themselves as to condition and must understand that any statement made by Sotheby's is merely a subjective, qualified opinion. Prospective buyers should also refer to any Important Notices regarding this sale, which are printed in the Sale Catalogue. In particular, please note it is the purchaser's responsibility to comply with any applicable import and export matters, particularly in relation to lots incorporating materials from endangered species.NOTWITHSTANDING THIS REPORT OR ANY DISCUSSIONS CONCERNING A LOT, ALL LOTS ARE OFFERED AND SOLD AS IS" IN ACCORDANCE WITH THE CONDITIONS OF BUSINESS PRINTED IN THE SALE CATALOGUE."

**Please be advised that bands made of materials derived from endangered or otherwise protected species (i.e. alligator and crocodile) are not sold with the watches and are for display purposes only. We reserve the right to remove these bands prior to shipping."

This exceptional chronometer was almost certainly made for the purposes of land survey and may well have belonged to the Royal Board of Ordnance, the coronet and GR cipher engraved on the dial denoting the Board’s ownership. The first ordnance survey map (of Kent) was published on 1^st January, 1801 and about a third of England and Wales was mapped at the one inch scale over the next twenty years.

Robert Pennington was active in Camberwell from c. 1780-1816. He was an important member of a team assembled by Thomas Mudge Junior to produce marine timekeepers to his father’s designs. Approximately 30 of these Mudge timekeeper copies were made in the latter part of the 1790s. Pennington’s contribution to the development of precision timekeeping included an improved and lighter form of bi-metallic compensation balance that incorporated screws rather than weights.

The present marine chronometer has an early form of the so-called ‘YCC’ balance which is the first of four types accredited to Pennington (see Vaudrey Mercer, Antiquarian Horology, Spring 1981). It was Pennington’s balances that led directly to the bi-metallic balance, used almost universally for the rest of the 19^th and much of the 20^th century.

The double mainspring barrel assembly is similar to that employed by Thomas Mudge in his No. 1 timekeeper. When the present chronometer by Pennington was sold at Christie’s in June 1996, it was noted that both springs were signed K Clark, it is likely that the K is an R for Robert Clark who is known to have worked for John Roger Arnold, and almost certainly others. Anthony Randall in Watches in the British Museum (V1, 1990, pp. 181-182) provides details of the system, calculations and a diagrammatic drawing by David Penney. The system has the advantage of allowing less frictional loss of power at the fusee and barrel pivots and the combined lengths of the two springs allow for a lower reduction in the gear train, again resulting in lower frictional losses in the train. These advantages are partially offset by the reduction in available height and barrel diameter. The movement is wound via an external mechanism of Margetts-type, which is accessible in a recess of the hexagonal mahogany two-tier outer case.