1675 – 1700 – The Balance Spring
1700-1775 – Steady Progress
1775-1830 - The First Chronometers
1830-1900 – The Era of Complications
1900 Onwards – Metallurgy to
Prior to 1600 – The Earliest
Before 1600 the main problem in portable timekeeping was the
driving power. Typically, the timepieces of the day were driven
by weights, and therefore were impractical to transport on
In 1524, 15 florins were paid to Henlein for a gilt musk-apple
with a watch. This was the earliest known date of a watch being
produced. Other watches appeared in 1548, and were probably of
German or French origin. The Swiss and the English products do
not occur till about 1575.
In the horological industry, this period was one of great
advancement and innovation.
The first movements were made of steel, but brass movements
appeared shortly thereafter  .
The first movements were straight verge movements, with no
balance springs. These first timepieces were notoriously
inaccurate. Most watches had only the hour hand and had to be
wound twice a day.
It was before the introduction of the gear cutting engine and
steel production was not as precise as it is today. The
variations in quality, and the fact that many steel alloys had
not even been discovered at this time, meant that timekeeping was
not the art it is today.
In this period, the first use was made of the spiral-leaf main
spring. This was crucial to the production of the first watches,
as it allowed horologists to power a movement without the need
for the common hanging weights. This however, opened up a whole
range of problems for watchmakers. Typically, a spiral
spring’s tension will not be constant from fully wound to
unwound. Thus watchmakers found a significant difference in
timing between the short arcs 
and the long arcs .
In an attempt to reduce this spring force error, the
watchmakers found that they could increase the accuracy of their
timepieces by using only a portion of the mainspring that
produced nearly linear tension on the train. This helped, but in
the quest for better accuracy, other methods of providing
constant torque on the train were tried.
The stackfreed was a German invention that had a cam at the
end of the barrel arbor  . The
cam had another spring (leaf) acting on it that attempted to
compensate for the variations in spring tension.
The English and French solution was to use the fusee. The
fusee improved the regulation of spring tension markedly, and was
used extensively till the 1900’s. The first fusees stopped
the clock during winding.
In an attempt to prevent over oscillation of the balance
wheel, stops were also included as a crude form of regulator.
These stops were typically of stiff hog bristle.
At that end of this period, astronomical data and dates were
already being displayed on watches, but even with all these
embellishments, timekeeping was still very poor.
1600-1675 - The Age of Decoration
This period saw little in the way of technical innovation, but
watches were becoming more a jewelry piece . The cases were of gilt metal or precious
metal, and were engraved, jeweled, pierced and enameled for
decoration . Thus the watch was
seen as a piece of jewelry that was more or less ostentatious
depending on whether it was exposed (pendant) or not (pocket
The shapes of cases went from a tambour cylinder  with a lid to being circular,
with hinged, domed covers front and back. Decoration included
champlevé enamel and relieved cases filled with coloured enamel.
To protect the intricate cases the manufacturers supplied a
protective outer case that was designed to be worn together with
the watch. This was unimaginatively known as a pair-case watch.
Glass crystal was fitted to the cases around 1620, but it was
usually as an alternative to a metal opaque cover. The glass was
translucent only; therefore the owner was still unable to see the
time without removing the cover.
The owners still had to open the covers to wind and regulate
the watches; therefore all parts of the cases needed to be
attractive. The main form of internal decoration was piercing to
the balance cock and fine work to the pillars, such as tulip
On German watches, the Arabic ‘2’ was usually shaped
like a ‘Z’. Dials usually had an outer chapter marked
I-XII and an inner chapter marked 13-24. This was to accommodate
the 24-hour convention used in Italy, Bohemia and southwest
Germany. The inside chapter ring was usually engraved with a star
or rose. The hands were always of steel and carefully shaped.
In England, unornamented watches became popular around 1625,
as a result of the Puritan movement. After 1660, exuberant shapes
and adornment were usually confined to women’s watches.
1675 – 1700 – The Balance
While a spiral spring was first used for the mainspring in
around 1500, it was not until 1675 that a spiral balance spring
was used. This one step took daily timekeeping accuracy from
fractions of an hour to fractions of a minute  .
There is some dispute as to who first applied the spiral
spring to balances. Both Huygens and Hook were working with
springs, but Huygens worked with the spiral spring whereas Hook
has attributed to working with flat springs. Hook also worked
with Tompion, a master craftsman of his time. Tompion also
invented an adjustable rack type regulator, with bristle curb
springs, for the balance spring.
The main hope when the balance spring was introduced was that
it would make the balance isochronous 
, but this hope was dashed when it was found that temperature
affected the rate, because of the elasticity of the mainspring.
With the increase in accuracy it was also noted that the
position of the watch had an effect. The watch would gain or lose
time depending on the pendant and face positions .
Because accuracy had increase so much, a minute hand and a
dial subdivided into minutes was added. The face convention was
to have the hours marked in Roman numerals and the minutes in
Arabic numbers. A fourth wheel was also added so that the watch
could be wound once a day instead of every 12 hours.
In 1675, Charles II of England introduced long waistcoats.
This became the fashion, and men’s watches were then worn in
pockets of the waistcoat instead of pendant style from the neck.
After 1690 the use of three wheel trains is very unusual,
being restricted to old-fashioned watchmakers. The four-wheel
train and six-leaf pinion were just about universal.
For a short term before and after the century, the makers of
low class watches placed the balance immediately under the dial.
The balance was visible through the dial, and it was intended to
trick the unwary into believing the watch had the supposedly
attributed powers of a pendulum, which was fashionable at the
1700-1775 – Steady Progress
In 1704, English watchmakers Facio de Duillier and P. and J.
Debaufre developed methods for using jewels as bearings. By 1715,
this practice was still rare. After about 1725 it was common to
find a fairly large diamond endstone mounted in the cock.
However, even at the end of the period, only the upper bearing of
the balance shaft, i.e. in the cock, were likely to have jewels.
For nearly a century the art of jewelling remained exclusive to
After the turn of the century, makers paid greater attention
to lubrication. In about 1715 Sully discovered that forming a
small sink around each hole would retain the oil, due to its
surface tension. This was not usually found in watches before
The commonest watches of the period had pair cases in gold or
silver, both of which were plain. The casemaker’s initial is
found on plain gold and silver cases. Where a watch does not have
the same initials on the inner and outer case, the outer is
non-original. In good class watches, the watch number is repeated
on the cases. The gold cases of the period are 22 carat and
silver-gilt, brass-gilt and Pinchbeck 
are all found. Silver cases were rarely hallmarked before 1740  , although gold hallmarks are
fairly common. Dust caps were fitted to provide better accuracy.
The size of the English watch was 1.75 inches, down from 2
inches, and about one inch thick.
Dials were mainly champlevé, but were slowly replaced by
white enamel dials with block numbers. The earliest enamel dials
were somewhat dull and pitted, but after 1725 they are smooth and
polished. The markings on the face included bold Arabic numerals
for the hours. Most of the minute markings had disappeared or
made very small, and at 15-minute intervals. However, by the end
of the century the markings on the faces became much lighter and
more elegant. The maker’s name never appeared on the dials
before 1750. By 1775, champlevé was rare. In English watches the
hands were usually of the beetle and poker style, although the
hour hand sometimes had a tulip pattern. The hands were usually
made of black steel, although better class watches had blued
In single-handed French watches, it was common for the winding
square to be in the center of the dial, protruding through the
boss on which the hand is mounted.
After the initial flurry of technical development, decoration
then took over as a method of differentiation. From 1715 onwards,
repouse  and adornment  of outcases was the vogue.
After 1750 it declined and was rarely found after 1775. Pendants
became more elegant, and glasses were snapped in from early in
the century. Movement decoration still occurred even though they
were covered by dust covers. Balance cocks were very large  and were decorated and
pierced. On the Continent, the balance cock had no foot. It was a
circular bridge screwed at either end. From 1750 on, the foot
ceased to be pierced, and extra decoration was uncommon from then
to this day. Pillars became progressively simple, from tulip to
round and then square.
Up to 1700 there had been little change to the verge
escapement. In 1726 Graham refined the horizontal, or cylinder
escapement  . This was more
accurate than the verge, but also more fragile. Early cylinders
were made of steel, and the escape wheel of brass. This promoted
excessive wear on the cylinder, but this was corrected later. The
cylinder, as an escapement, had a run of about 200 years.
Early balance springs were soft and untempered, and very
easily distorted. The earliest springs had only 1.5 to 2 turns,
but by 1750 4 to 5 turns were more usual.
In 1740 Frenchman Le Roy introduced a screw adjusted sliding
plates containing pivot holes, so the escape wheel could be
positioned very accurately.
Lepine departed from the then usual practice of having the
movement between two parallel plates and the balance wheel
outside the top plate. He discarded the top plate altogether and
used individual cocks mounted on a single plate, including the
balance. This formed the model for manufacture of all watches to
the present day. The use of cocks made assembly and repair of the
watches much easier, and more importantly, made them much
thinner. Lepine also dispensed with the fusee and used a going
barrel to drive the train directly. This improvement was
facilitated by using the cylinder escapement and better springs.
In England, however, the verge and fusee were still used and,
at the end of the period it was generally acknowledged that
English watchmakers were producing the best watches.
English watches had the hour and minute hand, whereas the
continental watches of the same period tended to only have the
In the evolution to a detached escapement, non-detached
escapements other than the verge were also tried. The duplex
escapement  was invented by
Dutertre in 1720, and modified to be more usable by 1750. The
rack lever was invented by Abbe’de Hautefeuille in about
1720 and improved by Litherland in England in 1791.
Around 1750-1760 Mudge designed the detached lever escapement  . However, it was left to
others to refine the escapement to its present form. The main
problem with the first lever escapements is that the escape wheel
teeth had no draw  . It was
introduced much later by the Swiss, Leschot.
The first forms of the lever were with the lever arm at a
tangent to the escape wheel. English watchmakers preferred the
right angle arrangement, while the European watchmakers preferred
the straight-line lever.
The English right-angle layout was persisted with until the
first quarter of the twentieth century.
1775-1830 - The First Chronometers
In 1761  John Harrison
made a clock that was sufficiently accurate to be used to measure
Longitude during a sea voyage 
. In spite of this feat, Harrison’s clock did not contribute
significantly to horology as the timepiece was too complicated  . It was left to other
horologists  to produce a
practical marine chronometer and pocket chronometer.
The basics of the designs included a balance completely
detached  from the train, a
helical balance spring 
instead of a spiral spring and maintaining power whilst being
wound. All designs had some form of temperature compensation  . A fusee was still in use.
By 1800, the pocket chronometer was a readily available
With the newer, more accurate escapements, other changes
occurred to timepieces. A seconds hand  was added to the watches. Jewelling was
more extensively used, with some extremely large jewels being
placed on the visible plate 
. A ratchet and pawl mechanism was used under the dial, instead
of the usual worm and wheel. Plates were arranged to consider
servicing and repair.
Pillars and cocks had little decoration. Tompion’s style
of rack adjustment for the regulator was dispensed with and the
current lever with curb pins was introduced.
Bimetallic balances were still rare, and decoration was
minimal. However, the watch was finally accurate enough to be
used as a timekeeper, not just jewelry.
Verge watches were still in use in this period, and many of
the improvements were aslo applied to them. Bridges were added
for ease of assembly. This also required the repositioning of the
verge’s contrate wheel to the other side of the train.
Regulation was also upgraded to the newer, simpler style. The
watch diameter increased substantially, but the thickness was not
By 1830, pair cases were rare, except on a verge watch. Where
pair cases did exist, they were usually of silver or gold, with
various shaped pendants and stirrup shaped bows.
The watches were wound by opening a hinged back to reveal a
second fixed bottom pierced with a winding hole. The pendant was
a spherical knob often pierced by a push piece.
Dials were usually of white enamel. Roman and Arabic numbers
were both used, but Roman numerals were more common  . Dials with seconds hands  were flat and hands became
simpler. Materials used for the hands were either blued steel or
gold. The counter sinking of subsidiary dials was unusual in
English watches before 1860.
After 1800 dials in four-colour gold became popular  . This type of watch usually
had lustrous gold hands.
Around this period, the table roller lever escapement, which
was first used in 1823, was becoming established.
In Europe, the going barrel was replacing the fusee. Cocks
were small pierced bridges and the silvered regulator dial
continued. Some watches had a Chinese duplex escapment and this
produced a watch where the second hand moved only once per
While escapements such as the virgule and Pouzait gained some
favour, the lever was gaining strength of numbers all the time  .
The great Breguet started his own production in 1780. In 1787,
he produced lever watches in France, but it is not known if
Julien Le Roy preceded Mudge’s development of the lever in
England. Breguet produced straight-line lever layouts with a cut
compensating balance. Other Breguet innovations included a ruby
cylinder watch, the overcoil 
on balance springs, the ‘parachute’ balance staff
suspension  , a self winding
watch, or ‘perpetuelle’, the ‘tipsy’key that
prevented reverse winding and the tourbillion.
A Swiss called Perrelet conceived self-winding watches in
1770. Breguet produced them from 1780. Even though the
self-winding watch was invented then, not even Breguet’s
magnificent workmanship could make one that would work reliably
for a long period. He therefore gave up making the
‘perpetuelle’ around 1800 
Another difference between the English and European watches
was in the escape wheel. The English used a wheel with pointed
teeth and the Europeans used a wheel with clubfoot teeth. The
clubfoot teeth, as well as the pallets, provided lift to the
balance, whereas in the English version the wheel provided all
Pair cases began to go out of fashion by 1775, when the French
started to make thinner watches.
As a historical note, Breguet died in 1823.
1830-1900 – The Era of
By 1850, in England, the lever 
watch reigned supreme. By 1860 the design of the lever had
changed from a straight-sided design to a curved one. The fusee
continued till the last decades of the century.
Watches were thinning by using a three-quarter or half plate
movement. In the three-quarter movement, the balance, lever and
escape wheel were placed with separate cocks in a space obtained
by cutting away a section of the plate. In the half plate, the
fourth wheel also had a separate cock.
In 1814 Massey first used a push or pump winder with a rack
operated by pushing the pendant that turned a ratchet on the
fusee or going barrel. Various winding systems were devised
around the first and second decades, but the first man to devise
winding and hand setting through the pendant was Audemars in
1838. Initially the change of mode from hand set to wind was done
via an external lever, but eventually this was dispensed with.
With keyless wind and pendant hand setting, the cases had no
need to be opened all the time. A snap on bezel was introduced,
and the hinged back was snapped firmly shut, with a small lifting
ear to assist opening.
The dust cap changed to a small hinged cover fitted inside the
back, and the movement was screwed in place instead of being
England was still using fusees at this stage, and the keyless
wind and hand set were designed to work only with a going barrel.
It was not until the 1890’s that the English changed from
the fusee to a going barrel, but they still continued to use
The watches still used full plate movements, and extravagant
Liverpool jewelling was replaced with smaller jewels.
As the Victorian era progressed, cases and dials became
heavier to the eye and hands became slimmer.
With the introduction of the second hand, some makers provided
for the hand to be stopped like a chronometer. However, in these
early watches, stopping the seconds hand also stopped the whole
watch. The dials were divided to show fifths of a second and the
number of beats was raised to increase accuracy.
The first true chronograph 
, as we now know it, was designed in 1844 by Nicole. It was not
until 1862 that the contemporary three push  system was used.
Nearing the end of this period, watchmakers had devised
mechanisms for all the grand complications such as repeaters,
moonwork, alarm, striking, musical, automata, jaquemarts,
multi-dial, day, date, month and stopwork. A large proportion of
the watches with complications were Swiss with lever or cylinder
escapments. An English refinement was the karrusel  , patented in 1892 by
Bonniksen of Coventry.
It should remembered that up to 1840, watches were all
hand-finished, so that parts were not interchangeable. The Swiss
however, believed there was a market for cheaper, machine made
watches with interchangeable parts.
The designer of the first production machine was Leschot  . The main change was that
holes were drilled using a panotgraph, thus making the hole
placement repeatable. Parts therefore became interchangeable. It
was Frederic-Jalpy (1749-1812), however, that devised machine
tools that laid the foundation for mass production.
The Americans were the first to begin volume production,
probably around the 1850’s. Companies involved in watch
production had mixed fortunes, but the main ones were Waltham
(1850-1950), Elgin (1864-on ) and Hamilton (1892-on). A different
concept was followed by the Waterbury Watch Company, founded in
1878. They made a cheap machine made watch with only 54 parts. It
had a mainspring coiled behind the watch and the whole movement
turned once an hour. This was in effect a tourbillion type
watch, but the company failed with too cheap an image for their
The Swiss kept an ever watchful eye on the Americans and
started volume production of both cylinder and lever watches
around1880. Towards the end of the century, Roscopf introduced a
cheap pin pallet escapement, and this type of watch set the seen
for many years to come.
Markets like Turkey and particularly China imported watches
from England and later Switzerland. The movements in the Chinese
watches were particularly ornate, with each part intricately
engraved. Steel parts were blued or polished. The enamel dials
nearly always had centre-seconds hands which moved but once a
1900 Onwards – Metallurgy to
The main changes to horology in this period came not from
mechanisms but mostly from the advances in metallurgy. With the
introduction of the balance spring on the first verge watch,
horologists discovered the non-isochronous behaviour of the
balance due to both temperature and position.
In an attempt to cure the balance problem, self-compensating
balances were made with bimetallic properties, cut ends and other
compensations. However, they were usually able to compensate for
high temperature and low temperature but not for middle
In 1900, Guillaume produced an alloy such that when used with
brass in a cut, compensated balance virtually eliminated middle
temperature error  . He
further experimented and in 1919 it was possible to make a
mono-metallic balance of Invar controlled by an Elinvar balance
The other main change in this period was the form factor
change that allowed the move from pocket watches to wristwatches  . By 1930, the ratio of wrist
watches to pocket watches was about 50:1. Winding was by button
and hand adjustment by rocking bar or shifting sleeve. In early
designs or pocketwatch conversions, the strap lugs were simple
wire loops added to what appeared to be very small pocketwatch
cases. Hinged or snap bezels and backs were used. Dials were
white enamel or metal without decoration but the numbers were
sometimes made luminous. Watch glasses started to be made from
transparent plastic material which was less fragile, but tended
to scratch and yellow with age.
The pocketwatch continued till the end of the Second World War
(1945) but after that production was minimal  .
English production tapered off till it effectively finished in
1930. After the war however, production with new tooling began
again. The Swiss watch captured a large percentage of the
In the new watchmaking regime, two escapements won through.
The lever was used for expensive jeweled or partly jeweled
watches whereas the pin pallet was used in cheaper watches. The
cylinder escapement, after two hundred years of life, was finally
a casualty of a crowded marketplace.
In 1945 quality wristwatches began to get complications that
had been available in pocket watches. The main complication was
the Perrelet method of automatic winding  . The chronograph became available, often
with datework, alarmwork and moonwork etc. Watches were also made
more robust, with mechanisms to make them waterproof, shockproof,
and able to function in extremes of pressure, vacuum and gravity.
With so much standardisation it was now not possible to
distinguish a brand’s national identity.
The battery-powered watch was available in 1952 as an
alternative to the automatic. The electronic watch, which
replaced the escapement with electronic vibrations of a tuning
fork, was a completely new concept. This changed the beat of the
watch from about 2.5 beats per second for a mechanical watch to
nearly 2.5 million beats per second for an electronic watch.
This new technology was embraced and enhanced by the Asian
watch industry, Japan in particular. This system allowed cheap
and very accurate watches to be mass produced in the millions.
By 1970’s , these electronic watches were so successful
that the mechanical watch was nearly lost forever. The resurgence
in the mechanical watch was brought about mainly by the nostalgia
of the Italians. Now the market for mechanical watches is
flourishing again, mainly in the upper sections of the
marketplace. Thirty percent of most Swiss watchmakers production
is mechanical, with over 6 million movements and ebauches
produced in 1995.
Manufacturers like Blancpain, Rolex, Patek Phillipe, Audemars
Piguet, Jaegar LeCoultre, Lange & Sohne and Vacheron
Constantin all make high quality mechanical watches..
The Watch Collectors Handbook, M. Cutmore, David and Charles,
Investing in Clocks and Watches, P.W. Cumhaill, Barrie &
Rockliff, London, 1967.
Brittens Old Clocks and Watches and their makers, Britten, FJ,
Eyre Methuen, London, 1973.
Britten’s ‘Watch and Clock Makers’ Handbook, D.
Van Norstrand Company, Inc 1955.
Europa Star Magazine, Gallery, Mechanical Watches. Pierre
Maillard, Pascal Brandt and Maria Finders.
Many snippets from contributors on the Internet, ebay in
 It should be noted that
forgeries are not restricted to modern times. Abraham-Louis
Breguet (watches c1780 onwards) had people forging his watches in
his own lifetime (al-la Rolex today) and he included a secret
signature on his dials to show authenticity. Tompion, Graham and
Arnold also dealt with forgeries during their own time.
 It may appear that reason
for the change to brass was to do with the properties of the
metal. The properties that are appealing include ease of working,
corrosion resistance and reduction in friction. However, the real
reason was that different Guilds (trades) that were involved in
the manufacture of watches. In the first instance, the two guilds
that were permitted to make watches were blacksmiths and
locksmiths. Blacksmiths obviously worked in steel and the
locksmiths in brass. However, when watches became smaller and
smaller, it was the locksmiths that were more able to adapt their
metal to the requirements of the watch, Thus most movements were
made of brass, not steel.
 Mainspring nearly unwound.
 Fully wound mainspring.
 The stackfreed was not
adopted by any other country and thus is found only in watches
made in Germany
 Towards the end of the
period a fusee chain replaced the fusee gut.
 Surviving cases for the
period were usually of thick base metal, so that the artisans
could show their capabilities by fine engraving. It is suspected
that precious metal cases of the period were melted down when the
watches broke or retired from use because of their woeful
 ie in the shape of a drum.
 All this talk of the woeful
accuracy of timepieces does not indicate that correct times were
not known at all. The astronomers were able to determine very
accurately the "same" time from preceding days by
viewing the positions of the stars. Clocks improved in accuracy
and was usually an order of magnitude better than a watch. This
was due mainly to the availability of a constant driving force
(weights) and a (nearly) isochronous pendulum for regulation.
 The time of oscillation,
or period, would be the same regardless of the strength of the
mainspring, or the arc of movement of the balance.
 These same problems,
position and temperature, still apply to mechanical watches
today. Some inventions, like the tourbillion, have
attempted to reduce or minimise the errors, but they have not
 Pinchbeck is an amalgam
of copper and zinc intended to imitate gold.
 The Sterling Silver
Standard (English) was abandoned from 1696 until 1720. Silver
bullion was used mainly to mint their coinage, To obtain silver
bullion, people "clipped" some off the edges of the
coins, then melted it down to form an ingot. In 1696, a new
statute recalled the old silver coins and new coins were issued.
The Act also prohibited the use of Sterling Silver for making
spoons, tankards, watchcases and other items under a severe
penalty of 500 pounds fine.
 The hammering of a
design from the other side of the case.
 Mostly inlaid with
tortoise shell or precious metals covered with translucent horn.
 Because of large balance
 Tompion, in co-operation
with Edward Booth and William Houghton, invented the cylinder
escapement. It was patented in 1695.
 This escapement was used
mainly in England.
 The first lever watch
ever made was constructed in 1759-1760 by Thomas Mudge, for
George III and was given to him by Queen Charlotte. It needed
winding only once year. It still resides with a royal family, who
can recount nearly everyone who has ever wound the watch.
 This is a form of
undercut to a tooth so the pallet is held firmly in contact with
 Britten’s book
gives this date as 1759.
 The actual contest,
started in 1714, was to determine the latitude during a journey
from the British Isles to the West Indies. The rewards offered
were for E£10,000 for an accuracy of within one degree,
E£15,000 for accuracy within 40’ and E£20,000 for accuracy
within 30’. The reward was offered by the Board of Longitude
in England. The voyage would take about six weeks and the
chronometer could not be out by more than 3 seconds a day.
 Only three of the
patterns were ever made, Harrison # 3 and # 4 and Kendall # 1.
 Such as Pierre Le Roy,
in 1766. The Le Roy chronometer had a detached escapement and
compensated balance, whereas Harrison’s did not. In England,
by 1780, Arnold and Ernshaw evolved a design that has been the
model for marine chronometers ever since. They were both bitter
rivals and accused each other of plagiarism. The absolute
determination of who was first has never been established.
Frenchman Ferdinand Berthoud also reached the same point at about
the same time. The Englishmen made about 1000 chronometers,
compared to Berthoud, who made about 70 in the same period.
 This feature means that
the only friction on the balance is when impulse is given to the
 A helical balance spring
can be made isochronous more easily than a spiral spring.
 The most common form of
temperature compensation was a bi-metallic balance.
 This was usually placed
in a subsidiary dial above the six hour mark.
 This is sometimes called
Liverpool jewelling, indicating the importance of the Lancashire
watch industry at the time.
 In Europe, Arabic
numbers were more common.
 Seconds hands were not
 Four colour gold was
made by mixing other substances to give red, yellow, green and
white tints. The dial would be one colour and the numbers of
another colour would be soldered to the face. Finally a two-tone
band of foliate would be on the outside.
 In Switzerland however,
the cylinder escapement was starting a run in production that
lasted about 200 years.
 The overcoil, to make a
spiral spring isochronous, was Breguet’s lasting legacy to
horology. In a watch with an overcoil, it is not possible to
regulate the balance.
 This consisted of two
spring steel arms that housed the end stones of the balance
shaft. The arms were lone enough to provide sufficient deflection
that an excessive jar would deform the arms before breaking the
balance staff pivots. The arms would then spring back to the
 It was not till about
1930 that wristwatches were fitted with successful self-winding
 Right angled lever
 A watch that could
measure the start and end of an event without stopping the mean
 Start, stop and reset.
 The karrusel was
a simpler version of Breguet’s tourbillion, which
compensated for positional error.
 This was the same man
who introduced draw into Swiss lever escapements and designed
standard tools to make lever escapements.
 This was actually called
a Guillaume balance.
 The main instigator for
change was the First World War, where it was found that
wristwatches were more convenient than pocketwatches.
 One of the main
contributors to this was exactly the thing that increased their
popularity in 1675. The waistcoat was the falling from fashion.
 A problem of autowinding
in the wristwatch was over supply of movement, whereas in the
pocketwatch the reverse was true.