Notes
Josiah Emery (c. 1725-1797).
ASwiss watchmaker, born in the canton of Vaud, near Vevey, settled in England and had a shop at 33 Cockspur Street,
Charing Cross, London. He made very fine cylinder watches, but became famous as the first watchmaker in the world
after Thomas Mudge to produce a watch with a lever escapement (the present lot). He made about thirty-six lever watches
between 1774/5 and 1795. Three of Emery?s lever watches were imported into France and served as a model for Robert
Robin for a series of precision watches that he produced at the end of the eighteenth century. One of these watches was
shown to Louis Berthoud, who used the escapement several times and attempted to improve it, but finally abandoned it in
favor of the pivoted detent escapement. He also used the pivoted detent escapement for precision watches.
In 1782, Emery patented his ?double S? balance, a fact which he advertised widely. Most of Emery?s ?double S? balances
are found in his lever watches, which he started making in 1782, the year of the patent. He produced less than 40 of them,
of which fewer than 12 are known to have survived, making the ?double S? balance even rarer.
Emery submitted four chronometers to the ?Office of Longitude? between 1792 and 1796, but obtained no success with
them. He studied and corrected the error of the escapement of the chronometer made by Genevan clockmakers Demole &
Magnin. His workmanship is always superlative, equal to the best of his contemporaries, including Arnold. Louis Berthoud
said of Emery?s work that it was particularly good in its essential points, and not ?showy?. In 1781 his excellence was
recognized by his peers, who elected him an Honorary Freeman of the Clockmaker?s Company, a distinction rarely given.
He was succeeded by Recordon and Dupont in 1796.
Because it incorporates one of the earliest known experimental examples of the lever escapement, this unique and quite recently
discovered watch can be described as being amongst the most historically important English watches in the world. Josiah Emery?s
numbering system was very consistent and the number 661 can be linked fairly accurately to the years 1774?1775. With the
exception of the balance spring, the lever escapement was the greatest single improvement that has ever been applied to watches.
In addition, this watch has an early automatic device for compensating changes in temperature and center seconds that can be
stopped independently of the rest of the movement. Thomas Mudge invented the lever escapement in 1754 but the first watch to
incorporate this important innovation was not made until 1770. That watch was acquired by King George III for Queen Charlotte
and was referred to as the ?Queen?s watch? in correspondence between Mudge and his patron Count von Bruhl, Saxon
Ambassador to Great Britain, when it had been returned to Mudge's Plymouth workshop for alterations and adjustment in the
early 1770s. Mudge subsequently described his invention as ?the most perfect watch that can be worn in the pocket, that was
ever made?. The present watch is closely linked to the ?Queen?s watch? by Count von Bruhl who approached Emery and tried to
persuade him to make watches with Mudge?s lever escapement. Bruhl described the escapement to Emery in about 1774 but we
know that Emery had not seen the ?Queen?s watch? nor any model of it. Therefore, the present watch was almost certainly made
as a direct result of his conversations with Bruhl. We know that Emery was experimenting around this time with a number of
different ideas to make a precision timekeeper, his watch No. 615 (hallmarked 1772-3) and made just a year or so before the
present watch, No. 661, was heavily influenced by Harrison?s publication ?Principles?, 1767, and was fitted with Kendall?s
escapement which proved to be a poor design. By 1778, Emery had moved on to using Arnold?s pivoted detent escapement which
had been shown to be highly successful from the mid-1770s. The making of the present watch therefore falls between these two
periods and shows Emery?s experimenting with the strange new escapement described to him by Bruhl and interpreted by Emery
directly from Bruhl?s description of the ?Queen?s watch?. This watch was very likely to have been made almost entirely by Emery
himself, largely to ensure its existence remained a secret until he had seen how it would perform. This said, it is possible that
other makers might have seen this watch and been influenced by it. For instance, the early lever watches made by John Leroux
in the mid-1780s have an identical escape wheel, and as in the present watch all the lift is on the teeth. This would explain the
otherwise anomalous lever escapements made by Leroux at this time. The train of the present watch determines a balance
frequency of 36,000 beats per hour, this is almost certainly a uniquely high frequency for an eighteenth century watch.
The Stages of Development of Emery No. 661
In common with the makers of most experimental machines, Josiah Emery maker did not immediately produce this watch in its final
form, but rather improvements and developments resulting from experimentation with the various components were introduced and
adjusted as time went by. This watch appears to have had two distinct previous ?states? before reaching its present form.
First State
In 1774/5, Emery had the movement signed and numbered in case he might one day want to claim it as his product and maybe even
sell it. Giving a serial number might also have been a means of staking his claim to the overall movement design. At this stage the
movement is likely to have been ungilded and uncased, it almost certainly had no maintaining power and appears to have had a
straight, Harrison-type bimetallic compensation curb acting on the tail of the balance spring. The curb would have been mounted
on a pivoting slide plate, for meantime adjustments, centered on a hole in the potence plate that has since been removed and a piece
of brass dovetailed into the back plate. In its first form the balance spring would have been studded in a position about 90 degrees
from its present position ( a plugged hole of the correct size is there) presenting the extended curved tail in the correct orientation
for the curb to act upon it. An arc of 20 dots on the back plate marks the span over which the curb would have operated. The balance
and spring is where we see further influence of John Harrison. The extraordinarily high frequency of the train is undoubtedly
inspired by Harrison, who implied in ?Priciples? that the smaller the watch, the faster the train should be.
Second State
Approximately two or three years later, the maintaining power was fitted, such a high frequency balance associated with an
experimental type of lever escapement meant that the watch was not self-starting, although reasonably reliable once going.
Without maintaining power, it would need a good twist to start it after every winding. The pillar closest to the fusee has been
considerably cut away to make room for the new maintaining power detent and the fusee itself has been fitted with a peculiar,
small maintaining power wheel hidden between the fusee and the great wheel necessitating the detent to be thinned to a sliver
in order to fit into the groove. The compensation would have been changed at this time and also the area of the back plate
containing the hole for the previous compensation slide cut out and plugged with the dovetail piece. The entire movement would
have then been gilded. The new compensation is of ?Chelsea bun? type and fitted into the original slide-plate but with the compensator
filling the opening for it fully. The balance and spring were positioned in their present place at this stage to work with
the new compensation.
The final stage of the making of this watch occurred probably in the 1790s and perhaps after Emery?s death. At this stage, the
changes were purely additions and not alterations. It is very likely that up until this point the movement had never had a dial or
case. The present case, dial and hands date from this period and are therefore original. It is possible that watch No. 661 remained
Emery?s property until his death and was among the effects that came to Recordon & Dupont in 1795 and they had the watch
dialed and cased to sell it.
?Josiah Emery, Watchmaker of Charing Cross?, Antiquarian Horology, Vol. XXII, pp. 394-401 & pp. 510-523; Vol. XXIII, pp. 26-44,
pp. 134-150, pp. 216-232.
We are grateful to Jonathan Betts of The National Maritime Museum, Greenwich, London, whose report on this watch forms the
basis of this catalogue entry.