The single, enamel dial plate has a separate circle for hours/minutes in the upper part and seconds in the lower, signed in between: ‘No.10 - (+symbol of anchor)’ and ‘BARRAUD – CORNHILL’. The dial would originally also have been signed by Howells, Kennington and Jamison, Portsea, but these have been erased. The timekeeper has polished blued steel beetle and poker hands with a fine pointer blued steel second hand with a counter poise.

The timekeeper has a fine, one-day full plate, gilt brass movement with four turned pillars, and reversed fusee, which has Harrison’s maintaining power, and single standing barrel. It has a four-wheel train plus a great wheel, with the fourth wheel incorporating a separate reverser for the second hand. The potence plate is signed: ‘LONDON / Howells Barraud and Jamison / No.10. 1796’.

It has an Earnshaw spring detent escapement mounted on a circular platform, which is itself mounted on the potence plate with the detent inset into the platform. It also has a two-arm bimetal, screwed balance with a blued steel helical balance spring. The jewelling extends to the balance (diamond upper endstone in a blued steel setting) and escape wheel, with endstones, and the fourth holes.

The timekeeper is contained in a three tier, brass bound mahogany box, 200mms high, 200mms wide and 200mms deep, with a hollow-lozenge inlaid brass shield escutcheon the front. The front of the upper half also has a circular ivory tablet, engraved: ‘BARRAUD / No.10 / ONE DAY / ↑’ and a scalloped star inlaid brass surround to the lid push-button. The movement of the timekeeper is housed in its original glazed brass case, with convex glass over the dial, and held in gimbals in the box.

The timekeeper has had a number of alterations over the years, most significantly having had the Mudge type escapement replaced in about 1820 and then having a conventional three tier box fitted, probably in the 1890s.

The chronometer was purchased by the Board of Longitude from the makers and was in R.N. service, in one form or another until 1967 when it was placed on permanent loan to the Royal Greenwich Observatory as part of its historic collection of chronometers.

The ‘Mudge copy’ timekeepers were produced between 1794 and 1797 in a short-lived manufactory established by Thomas Mudge Junior (1760-1843), the son of the celebrated chronometer pioneer, the London watchmaker Thomas Mudge (1715/16-1794).
Mudge Junior established the factory to produce timekeepers on his father’s plan, with the intention of proving their design was sound and partly in the hopes of making money. Sadly neither aspiration was successful, owing to Mudge senior’s highly complex constant force escapement and the fact that the instruments were finished to a superb (and very expensive) standard with the whole movement gilded and the dial with top quality enamel dial plates and pierced and chased silver spandrels. The cases for the copies were very elaborate too; the movements were mounted in a fine, glazed, brass inner case, which was in turn fitted into an octagonal mahogany case, itself then mounted on trunnions in a square mahogany box.

Mudge Junior initially employed two highly respected watchmakers to operate the factory; William Howells, who would make the complex escapements and Robert Pennington, who oversaw the movement making and made the trains, the two in charge of a number of other craftsmen under them. The factory was set up on Howells’ premises, which was to prove the first of many mistakes made by Mudge Junior in this enterprise. Work started on the timekeepers in 1794 with the eighty year old Thomas Mudge Senior advising for the first few months before his death in May that year. These first instruments were signed ‘Howells and Pennington, For Thomas Mudge’ and dated with the year of completion. These instruments will be referred to as ‘H&P’ timekeepers.

Problems appeared almost immediately, as the instruments were so complex and difficult to make and adjust, and after eighteen months, only eight were complete. At this point (1796) Mudge Junior tried to introduce more craftsmen to speed up production and a row broke out with William Howells leading to Mudge dissolving the agreement and having to move the factory to another site, leaving Howells, now a rival, with a ready made factory.

Howells immediately went into partnership with Paul Philip Barraud (probably as entrepreneurial financial backer) and George Jamison (probably filling Pennington’s role as frame and train maker) and started to manufacture simpler versions of Mudge’s chronometer design (to be referred to as ‘H,B&J’ timekeepers). Among many technical simplifications, these instruments had a single mahogany box and plain white enamel dials without silver spandrels.

At the same time, Mudge Junior now employed the respected escapement maker Richard Pendleton to fill the gap left by Howells, and the timekeepers made by this new set up (still to Mudge’s high specification) were signed ‘Pennington, Pendleton and Others, For the Son of the Inventor’ (‘P,P&O’ timekeepers).

Both manufactories considered themselves as a continuation of the first factory, so the numbering of the instruments began as H&P numbers one through to eight, but then both H,B&J and P,P&O run from nine onwards!

However, neither manufactory really succeeded in making the projects work as the timekeepers were just too complex ever to be reliable in the long term. Production by Mudge Junior’s factory had ceased by 1798 after about twenty-seven timekeepers had been created (including the first eight), though not all were finished. Howell’s partnership fared even less productively, splitting up in 1799 with only about seven instruments being produced and most of those probably incomplete.

Looking at all the evidence, it now seems likely that Mudge Junior, by this time thoroughly tired of the whole expensive saga, sold out ‘lock, stock and barrel’ to Paul Philip Barraud. Then, in the early years of the 19th century, Barraud had the whole remaining stock of timekeepers from both manufactories converted to the tried and tested spring detent escapement and sold as working chronometers, renumbered to fit his own current sequence.

Of the twenty-seven made by Mudge’s manufactory we now know of the existence of eighteen instruments (table of known instruments).