a brief glossary of technical terms

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A BRIEF GLOSSARY OF TECHNICAL TERMS

Words in red and in italics have an entry of their own elsewhere in this Glossary.

AIGUILLES

a Swiss or French key-wound watch is sometimes stampedthe nearby hole rather than by placing the key directly over theal.

ALARUM

or a clock or watch that sounds a warning bell at a pre-set time.echanical timekeepers and were being fitted to watches before 1600.

AMERICAN GAUGE

ze 0 equals 1.167" or 29.63mm and each step upwards orize 18, the largest in common use, is 1.688" (45.72mm). Sizes

and so on downwards, 1/0 being omitted. The Americaneasures the diameter of the front plate. ² This is a greatly simplified

ferent systems, I recommend this page in Wayne Schlitt's Elgin site.

ANCRE

th-century form, with the arm that carries the pallets mounted at ass to an anchor.

ARBOR

.

ARCADING

-century watches; between each pair of hour numerals the track isecially associated with Dutch watches (example).

ARNOLD, John



onometer pioneer. Born in Cornwall, Arnold first distinguished himself in 1764 with a tiny repeater sethe presented to King George III. He invented a helical balance-spring which came nearer to trueanything else before Breguet (who greatly admired him) produced his overcoil spring, and he may orised the spring detent escapement independently of Earnshaw .

BALANCE

ut a pendulum, controls the speed of the mechanism by itsriably consisted of a spoked wheel (for an earlier form seeis task alone, relying (not very successfully) on the weight of motion; since then the hairspring has provided this uniformity.

BALANCE-SPRING

is preferred in the U.S.A. but is not unknown in Britain; in 1857ng¶ [sic] for a watchmaker.

BALANCE-STAFF

very thin (to minimise friction) and therefore easily damaged,cumbs to accidental pressure on the unsupported cock .

BANKING PIN

ent ± a balance-wheel or part of the escapement ± from swingingnd designed to strike an obstacle if the arc threatens to become. Another kind is fixed to one of the plates and acts as a

BARRED MOVEMENT

laced by a number of small brass blocks screwed into place, eachuet as a variant of the Lépine calibre and became almost universale movement¶.

BEAT

s into contact with the escape-w heel .

BEETLE HAND

sh watches. Something like a figure-of-eight laid on its side,t of the hand near its outer end; this is supposed to resemble the

BERTHOUD, Ferdinand



spring detent escapement independently of his Englishg-enduring family firm, he is equally important for a series of of whom Berthoud reproachfully commented ³He has published

BEZEL

d. It forms part of the case and was usually hingedreaded or snap-on bezels gradually came into use.

BIMETALLIC

th the idea that their differing rates of expansion and contractionncel each other out, immunising the component in questione and hence in speed of oscillation. A bimetallic balance usuallys, split at two points to allow it to expand and contract withoutor purposes of fine adjustment. Such balances were used inme general until nearly a century later.

BOSLEY REGULATOR

round the centre of the cock , its outer end forming a pointer which movesFast[er], or in French R[etard] and A[vant]); near this end are fixed the

1755 but it is rarely seen before 1780; over the next half-century,.

BOTTOM PLATE

te farther from the dial.

BOW

dant of a watch case. The bow is often an approximate guide toused from about 1680 to 1820, after which a plain circular bow

BREGUET, Abraham Louis

r his individual ideas and incomparable craftsmanship. He

ate watches of austere beauty (his movements are quitewas an early champion of the lever excapement, although he alsonot invent) the ruby roller as found in most Swiss movements of 1840-1900.overcoil balance-spring, used in many quality watches of the 20th century

BREGUET HAND

m a circle, the latter having a hole cut in it slightly off-centre sor. The pattern was very widely used in both clocks and watches



rs from 1800. Also called moon hand .

BREGUET KEY

he wrong way it revolves harmlessly instead of straining the

English invention.

BREVET

ometimes mistaken for a maker's name ( ancre and remontoir alsohere really was a Paris watchmaker named Brevet, although ass the path of the average collector.

BRIDGE

ement, with a hole in it (often jewelled) to support one end of the arbor

BRIDGE COCK

n opposite sides. Bridge cocks were preferred by mostglish makers inclined to what I have called the cantilever cock ,

BRIDGE MOVEMENT

BULLSEYE

t or slightly concave in its centre, much used between aboutty years later.

CALIBRE

n may be said to be of stout, slim, massive or slight build, so alim etc. calibre. The word is most often found as part of the

CANNON PINION

w heel and has a tubular extension (whose shape gives rise to thehich the minute-hand is fitted. On English key-wound watchesy for setting the hands.



CANTILEVER COCK

but a coinage of my own for something which otherwise seemsh is secured to the dial at one point only, by means of a screw

nd whose table is prevented from collapsing onto the

CENTRE WHEEL

ion which shares its arbor ) from the great w heel . The arbor forms

CHAMPLEVÉ

ration used on very early watches. The metal body of the item to

ce only as a series of narrow walls between hollowed-out cellsme (µraised field¶). (2) A type of dial much used in theral is surrounded by a narrow platform following its outline, theengraved. The numerals themselves are engraved within theck wax.

CHAPTER-RING

ial which contains these numerals.

CHINESE MARKET

uropean (initially English, later Swiss) clocks and watchesg emperors setting the example. µChinese¶ watches usually haveporate a distinctive kind of duplex escapementin jerks like that of a modern electronic watch.s customary in the West. These watches are sometimes

CHRONOGRAPH

tch. Invented by Henri Piguet in 1861, it was a largege of the case to operate the stop-work. The minute/secondraph¶, unlike µchronometer¶, does not necessarily imply that

t so described.

CHRONOMETER

g a ship's longitude at sea ± a task which cal ls for exceptionale authorities hold that only an instrument fitted with a detent s argue that anything which performs like a chronometer (andonometer. True ship's chronometers generally have no cases,box.



CLICK

a wheel with angled teeth (in which the click engages) so thatassociation with one of the two large wheels usually visible in a

CLOCK-WATCH

sounds the hours etc. automatically as the appropriate timer is pressed. Some of the earliest portable timekeepers are

COCK

f the balance-wheel and to some extent protects the wheel

nd some German and Dutch movements until the 1820s, two feet)he balance. Until about 1790 the table covered the entireas compensated balances crept into use, the table was madeiercing died out, although engraving of some kind persisted

COLLET

ich holds the inner end of the balance-spring on the staff.

COMPENSATED

BALANCE eter (variations in which can affect its rate) remains constant atexpand and contract with heat and cold. This is usually donels (brass and steel) fused together so that their differingat two points so that the resulting fluctuations cannot cause it1800 but took nearly 100 years to penetrate throughout ther less as standard (c. 1880). See next entry for an earlier form

COMPENSATION CURB

etallic strip with one end fixed to one of the plates and thelled expansion and contraction of the strip adjusts the position of the

th. This device was first used in a watch designed by John Harrison

COMPLICATED WORK

recording and display of hours, minutes and seconds; e.g. calendars-phase indicators. The description is sometimes applied toisplays them on more dials than usual, e.g. by



CONE

d drum onto which the chain is wound and whosering effect. The cone incorporates the great w heel .

CONSULAR CASE

ches. The body of the case consists of an open ring to whichs the movement so that this can be swung out for inspection.sually pierced with a hole for the winding-key.

CONTRATE WHEEL

resembles a comb bent into a circle. Most often found in verge

CONTROLLER

modern watches an electronic vibrator ± which, in conjunctionthe watch and makes it a timekeeper. Where there is a separatean be considered as part of the controller.

COQUERET

of an 18th or early 19th-century French or Swiss watch. Thethe pivot; the other end is screwed to the cock. With the

r some adjustment of the staff.

CROWN

, turned by the fingers to wind the watch and (usually) to set the hands;hed in. Stem-winding is one of the few 19th-century Englishcision) watch-making, having been invented by Thomas Prest in 1820,

CROWN WHEEL

d because of the shape of its teeth.

CRYSTAL

dial of a watch (usually called simply µglass¶ until the late 19th900 and are now often found as replacements on older watches.hes for the glass or even the whole case.



CUPER family

ing family, hitherto buried in the pages of Bail lie's W atc hmakersEstablished in Blois before 1600 (Barthélemy, the earliest, was

he same town for nearly three hundred years, ceasing only withanches found their way to London, Geneva and even

CURB PIN

th of the balance-spring. Generally there are two such pinsey restrict its motion; they are mounted on an arm orhe length of the spring and allow a greater or lesser proportion

CUVETTE French watch, pierced with holes for winding and setting (if the's name, number, type of escapement and number of jewels.cap of an English watch.

CYLINDER

A type of escapement , especially popular in Switzerland between about 1840 and 1890, in wwheel interact with a cut-away cylinder which forms part of the balance-staff.

Brief Glossary of Technical Terms (continued)

DAMASCENING

sisting of a radial or striped design which appears to shimmer as it catchesmerican watches from the 1870s onwards. It is actually a variety of in mediæval weaponry, which is a technique of inlaying one metal in another.

DART

ts to prevent the lever and the roller from getting out of itself, between the tines of its fork; this fits into a curved recess

to lose contact with the impulse-pin and prevents the lever fromssociated with the European anchor-shaped lever and is rarely

DEBAUFRE, Pierre

n as a Protestant refugee. He was joint patentee with Nicolasnd in the same year he devised the first viable alternative to theerge¶ had two escape-wheels and a single pallet in the form of a



t away at one side and with its edges curiously angled and lop-sided (hence the name), which engagedlternately. This found some favour with Lancashire makers a century or so later.

DECK WATCH

chronising chronometers with one another or conveying theirere performed. For this purpose it had to be easily carried fromlly provided with its own case, unlike a true chronometer.

DENNISON, Aaron L.

-production, whose business, founded at Roxburym Watch Company.

DETACHED

tween the escape-w heel (or the final wheel of the train) and theecific processes of impulse and locking require them to be so.e is µdetached lever¶ (to distinguish it from the rack-lever ). Levertill a novelty, sometimes have the word DETACH'D engraved

DETENT

alance and the escape-wheel which performs the locking function,ovement impaired by the need to do this. The detent mayent of flat springs (spring detent ); the latter, devised almost

was for many decades the standard c hronometer escapement.

DIAL

am enamel dial began to appear at the end of the 17th century,tion have never quite gone out of use.

DOME

ierced with an access hole for the winding-key.

DOUBLE ROLLER ESCAPEMENT

carries two rollers: one carrying the impulse-pin and the other

DRAW

es it to pull the escape-wheel more tightly into engagement



process, producing an infinitesimal recoil in the train. The purpose of this is to prevent pallet andm slipping out of engagement,

DROP

he escape-wheel, and therefore the whole train, is free to turn.

DUPLEX ESCAPEMENT

t 1750 but favoured chiefly by English watchmakers in the firstsets of teeth (hence the name): short ones for impulse,for locking engaging with a tiny ruby roller (which tends to wear)

DUST CAP

om plate and sides of a movement, with holes cut in it for theish watches it is of gilt brass, removable and secured by ave silver dust-caps hinged to the movement.

EARNSHAW, Thomas

ovator. In early life he was a specialist maker of cylinderent escapement he was obliged to seek the co-operation of atain a patent until after John Arnold had done so, using a designshaw eventually established himself as a maker in his own right,o full chronometers; he led the way in offering the latter atduction. He devised the bimetallic compensated balance,

ÉBAUCHE

be bought in ready-made by µwatchmakers¶ who would thenry Swiss industry, while undoubtedly capable of producingvolume manufacture of ébauches. Frédéric J apy , by hissystem, gave the greatest impetus to this kind of activity.

ELGIN

at Elgin near Chicago in 1864, as the National Watch Company,

a manufacturing base beyond the traditional east-coastm. The Elgin name itself dates from 1874. In the early 1900scturer.

ENAMEL

coloured by means of metal oxides, which when heated (aan take a high polish. Enamelling of various kinds was usedt 1630 the French craftsman Jean Toutin discovered a means of



so that finely detailed portraits and scenes could be executed; this kind of decoration became ava and remained so for centuries.

first used for watch dials in about 1675 and gradually replaced the metal c hamplevé dial, becomingt 1770. Cream or off-white was favoured by English makers from about 1815 to 1860. They alsorface from about 1810, whereas the Swiss continued to use a high-gloss finish.

END PLATE

lance-staff pivot is located. In English watches (those withoutin place; the French school preferred a steel plate held by

ENDSTONE

ches, roughly cut diamond) used as an end-plate.

ENGLAND

ng school, and few examples by home-born makers can bey Queen Elizabeth I, was among the earliest. A Worshipfulfounder-members included Edward East, who was among theing away from the extravagant ornamentation that hadment of the balance-spring by Hooke and the discovery of theistinguished craftsmen such as Tompion and later Graham andntury. By 1800, however, English domestic watch design wasmained high (supported, before the 19th century was half over,akers remained wedded to the fusee and to full-plate or

er American producers were moving towards slimmer layouts. pool where new escapements such as the rack-lever and ther finally put an end to the multitude of local makers who had been-plate fusee levers virtually without change since the 1830s,

d to be made to the highest standards through the 20th century.

ENGLISH LEVER

e tangential or side lever .

ESCAPEMENT

e balance or other controller , breaks down the motive force of thely delivering impulse to the balance and locking the train. Itsthe latter may be mounted on or embodied in a separate

rated with the balance-staff ( cylinder , duplex , verge ).

ESCAPE-WHEEL

lly-shaped teeth which interact with the pallets.



FAKE FUSEE

watch with a going barrel and an extra wheel interposed betweene sole function of this extra wheel is to gratify old-fashionednti-clockwise like that of a fusee watch.

FALSE PENDULUM

the bob (flat circular weight) from the end of a clock pendulum,o that it could be seen wagging to and fro. For this purpose thee lay behind the dial, which had a slot in it through which thery revivals.

FASOLDT, Carl

ver escapement and pioneer of the production of true marine

FLIRT

hat moves in jerks rather than continuously, like the

FOLIOT

am with weights (which might be adjustable) at either end, like afoliots (only relatively miniature ± the foliot could take up theels.

FORGERY

ashionable London maker Eardley Norton was doggeda few of the makers went to the extent of counterfeiting the

ving on the bottom plate; but their coarseness of executionhortly afterwards Breguet became the chief sufferer; most

wiss master would not have touched, and they are often signedwatches often bear false names, usually English; W indmills orJ. Dent, whose family firm built Big Ben, the clock on the Housesrly Swiss. These old forgeries, unlike the modern fake Rolexeser than actual copies; the forger borrowed the name but not the

FORK

, with two prongs or tines between which the impulse-pin engages.

FORM WATCH



se is shaped to imitate something other than a watch: a heart, a cross, a book or even a skull. Formular in the late 16th century and again about 200 years later.

FOURTH WHEEL

subsidiary seconds dial is present, its hand will usually be fitted

FRANCE

-keeper very early; the Coudray family of Blois were producingch use of engraved decoration and their makers led the way inntury French watches were usually very deep in calibre, withs¶ (onions). The late 1600s saw the adoption of some featuresthe verge, such as the two-footed bridge cock and theeriod had very large balance-wheels. Enamel dials appeared inmetal dial with twelve small enamel plaques, one for each hour.ished and the division grew ever wider between run-of-the-mill

few outstanding craftsmen such as the le Roy family;

hough they worked in Paris (Breguet , Bert houd), and by 1800 the. Since then France, like England, has been chiefly noted for

tic watch rather than the chronometer; all the houses justuet still exists today.

FREE-SPRUNG

any kind of regulator effectively changes the shape of the springbeen the practice in instruments of the highest precision to dolies on the timing-screws for any adjustment that may beent will have been built and adjusted to a very high standard of occasionally needed. Free-sprung watches are therefore

FRICTIONAL REST

wing one component to slide over another without meeting anyal example is the cylinder escapement, where the cylinder itself hing the wheel backwards. By contrast, the verge is the recoiltooth meeting each other head-on.

FRONT PLATE

as the motion-work , set-up ratchet and (if present) repeater

and dial.

FULL-PLATE

g parts are sandwiched between two circular plates (usually of is not fitted between the plates but generally carried outsidelse pendulum or hebdomas watches, it may be placed behind the dialglish (and some American) watches is not strictly ful l, being cuta screwed-on bridge. Until about 1780 all watches were of



ion.

FUSEE

force of a mainspring as it unwinds by automatically adjusting

movement. Instead, it pulls on one end of a fine chain whosered parabolic-sided form, like a flattened pinnacle, with a spiralgo four or five times round the barrel. With the watch fullyso that the mechanical advantage is low ± in other words, theth a very small wheel or to turn a nut with a short-handledn off the cone, the diameter of the cone at the point of departure

age. The cone incorporates a ratchet and click for the windingnto it. English-style fusee watches, key-wound from the back,

da Vinci. Indispensable in early watches, it became lessstill less so as escapements improved in the 18th century.

with it as a regular practice. By contrast, fusees were still

A Brief Glossary of Technical Terms (continued)

GERMANY(incl. AUSTRIA)

uremberg was the first to make portable spring-drivenvements were often of iron rather than brass and includedThirty Years' War undermined the development of the industryds, although some individual features remained, notably thelatticework over the bottom plate. Among the outstanding

ily of Augsburg, whose activity continued for nearly 200 years.laborate watches with alarum mechanisms; at the same period

wn showing strong English influence. After 1800 the Swissermany, as from everywhere else; thus G. F. Roskopf based his

in the Franco-Swiss border town of Chaux-de-Fonds. In 1861,lock and watch factory at Schramberg in the Black Forest, anly 1700s; the firm of Junghans still exists, as does that of

5).

GOING BARREL

r than through a fusee. Going barrels are occasionally found ase and his followers from about 1780.

GRADE-NAME

a movement as if it were the manufacturer's signature, not withf the watch as the maker sees it. The dawn of the practice canand M. I. Tobias marked their lesser watches µBeatson¶ and

s chiefly American. Grade-names were chosen to honourrectors or (as in W alt ham's µAppleton Tracy¶) to document thee examples). They distinguish such features as the number of d on the movement at the factory; sometimes the graderailroad designation. A grade is not the same thing as a model;



as Waltham's Model 1883) may exist in several different grades, while one grade-name may beifferent models. The manufacturer's own name is usually shown as well, either on the dial or in aon on the movement. The practice may have been partly a means of preserving the traditionalback-plate, with a personal signature rather than that of a factory.

GRAHAM, George

f the dead-beat escapement for clocks and early champion of made no verge watches after 1727. Also noted for his

GRAHAM DIAL

of the period 1710-1765, with (reading from the edge inwards)rvals, a minute track , a roman c hapter-ring and a single circularm the early 1760s the inner circle began to be omitted and they were often omitted altogether, while the chapter-ring

GREAT WHEEL

(if present) or with the going barrel if no fusee is fitted.

GUNMETAL

ed brass as the preferred base metal for watch-cases. Alow-grade watch; many complicated movements of the periode so fitted.

HACK-WATCH

r under the dial which thrusts a wire hook between the teeth of theent. This device became popular soon after 1800 (concurrentlyith the medical profession in mind. Later in the century the

HAIRSPRING

h writers as µcolloquial¶ but certainly established in

HALF-CHRONOMETER

attern in using a pallet mounted directly on the escape-wheel tote element (a variant of the lever) for the locking function.

HALF-HUNTER



all crystal let into it so that the hands can be seen without

there may be a duplicate c hapter-ring painted near the centre of this chapter-ring is engraved on the cover itself and often picked

HALF-PLATE

fourt h w heel are located by individual bridges, the bottom plate

HAMILTON

ncaster (Pa.) as Adams & Perry in 1874; the Hamilton namees and other products of high quality, and was prominent in themperature changes) to balance-springs. Watch manufacture

HARRISON, John

tical marine c hronometer . Son of a village carpenter, Harrison20s he built several innovative clocks constructed almostprize appointed by Parliament in 1714 for a method of

30 (authorities differ) he travelled to London, bearing aescapement and a temperature-compensated pendulum; this

enerous loan. By 1736 Harrison had completed aal trial at sea; two more large machines followed

bmitted for the trials laid down in the 1714 Act.

uly portable, was sent on an official test voyage

y some members of the Board of Longitude) by

ut it was not until nine years later, and with the

the appointed reward. He made another

ere quickly superseded, but two of his inventions

t o the main stream of horological practice, while

of engineering.

HEBDOMAS

(the Greek word means µgroup of seven¶ and hence µweek¶).890, used an oversized mainspring whose barrel spanned thealance and regulator from the back; these items were thereforessible through a hole in the dial.

HELICAL SPRING

cylindrical configuration, in contrast to the usual flat or spiraleters.

HOOKE, Robert

microscope. He regarded himself as the discoverer of thens ) and undoubtedly formulated its theoretical basis in the



nsio sic vis (µthe power depends on the tension¶); he sems to have conceived the idea of applyingance many years before Huygens but not to have found a practical form for it. He probably devisedment for clocks and was certainly the inventor of a gear-cutting device which simplified clock ande.

HORIZONTALESCAPEMENT

y the fact that the escape-wheel lies in the same plane as the them, standing upright when they are horizontal.

HORN

for covering base-metal watch cases in the late 18th century.pattern ranging from reddish-brown to cream.

HOROLOGY

nt in time¶ and logos µword, speech, process of reasoning¶.not a practical constructor of timekeepers, although the twoent (Bert houd , Breguet , Harrison , Tompion etc.)

HOWARD, Edward

ennison in the early days of what afterwards became W alt ham.original Roxbury (Mass.) factory. Howard retired in 1882, butmade independently until 1903 when the company was takene name without loss of prestige until 1930.

HUNTER/HUNTING CASE

ose dial is completely covered by a spring-loaded hinged panelview the hands.

HUYGENS, Christiaan

er for the lute) and horological theorist; first to achieve ais design by Salomon Coster, c. 1656); probable discoverer of ted the precedency.

IMPULSE

balance which allows the power of the mainspring to bemoving instead of drifting to a halt.

IMPULSE PIN



ment, a pin made of ruby, mounted on a steel disc called the roller which is fitted to and concentric withThis pin engages in the fork of a lever and receives impulses from it, thus keeping the balanceed roller jewel .

ISOCHRONOUS/

ISOCHRONISM isochronous, or to show isochronism, when it takes exactlyirrespective of the distance covered; thus it beats at the samee ordinary flat balance-spring as introduced in the 1670s wass so with time through metal-fatigue, especially in verge

various special configurations to make this quality moref these and the only one which survives today.

JAPY, Frédéric

tion of machinery to the manufacture of watch movements,ansion of the Swiss industry in the nineteenth century.

JEWEL

ine, used as a substitute for steel where great resistance topivot of a wheel rotates. The pallets of a lever escapement arented by Pierre Debaufre and Nicolas Facio de Duillier in 1704English makers who thereby overtook the French as the world's

mmon after 1820. In reckoning up the number of jewels in athe roller jewel ; this last item accounts for the fact that the

movements (with cylinder escapements) it is frequently even.

JUMP SECOND/HOUR

oves from one step to the next in jerks rather than continuously.

KARUSSEL

of Coventry (U.K.) in 1894.

KEY-WOUND/KEY-SET

rate key, fitting over a square-ended shaft, for both winding perpetuelles, the idea of which was known in the 18th century.)

set by placing the key over the squared end of the cannon pinion;hole in the dial, while after that time both winding and settinginding persisted in Britain until after 1900.

LANCASHIRE GAUGE

s of watch movements, developed in Victorian times by theabout such as Ormskirk . It was based on units of one-thirtieth

.2", and so on up and down. Measurements were taken across



e front plate, not the case or even the dial. The American gauge is a development of the Lancashire.

LANCASHIRE WATCHCO.

l) in 1888 to introduce American methods of mass-production.

such traditional features as gilt plates, engraved cocks anded for badge-engineering, notably to J. G. Graves of Sheffield.1900s. Not to be confused with the Lancaster Watch

pany which afterwards became Hamilton.

LEAF

eel, is replaced by µleaves¶ when speaking of a pinion.

LÉPINE, Jean Antoine

with Voltaire and favoured successively by the Bourbons andnd inventor of the virgule; influential in reducing the thicknessdispensing with the fusee.

LÉPINE CALIBRE

the hitherto dominant full-plate layout by introducing ato support its outer end) and by mounting the balance cock on ating beyond it. This plan is known as the Lépine calibre. Thelternative to the full-plate or t hree-quarter-plate layout.the original form throughout the nineteenth century.

LE ROY, Pierre

nd pivoted detent escapements; built a chronometer in 1766,sed on the movement of mercury in thermometric tubes, whichnly depended on much simpler and more practical means toat sea were never followed up.

LEVER ESCAPEMENT

out 1840 in Britain and the U.S.A. (1890 in Switzerland) untill movements today. The µlever¶ is a pivoted bar to which isngage with the teeth of the escape-wheel; the other end of the

s mounted on a steel disc (the roller ) centred on thee in 1757 and applied by a few 18th-century makers includinghas two main forms: the side lever with the pallet-arm integralBritish makers), and the straight-line lever in which themerica from about 1870 and afterwards universal.

LEVER SETTING

ally concealed under the bezel ) which when pulled outward



which releases the motion-work from the train, so that the hands can be pushed round manually withoutning of the watch. This arrangement is found on many early stem-wound watches; pendant or stemsted because it was felt that the crown might spring out or be pulled out accidentally, allowing theof place.

LIFT

faces of the pallets and escape-w heel teeth which ensures thate between their respective paths. In the English or side lever ,y responsible for lift; in the straight-line type the teeth are cutts.

LIGNE

d in the Swiss industry for gauging the diameter of a movement., or 2.256mm.

LIVERPOOL

pidly in the second half of the eighteenth century under the twinntic traffic. Its vigorous watchmaking industry dates from this

ped the rack-lever and popularised the detac hed lever and the useovement found their way to the United States ²some exportedts ² and their influence is very noticeable in the earliest

LIVERPOOL WINDOW

wel , secured by two or three screws. Such jewels were common

LOCKING

is immobilised by the controller .

LONGITUDE

an agreed starting-point (meridian ± usually the meridian-line atminutes and seconds. Identifying a ship's longitude when outt by so many variables that it could scarcely be done by

n board an accurate timekeeper which showed the time at theip's location as determined by observation of the sun; thento terms of distance, but the clock had to be of outstandingds could represent as much as a mile if the ship were near thes the first practical solution.

LUNETTE GLASS

ith a two-stage curvature, steep near the bezel but much flatter



part of the surface. This style replaced the bullseye glass.


MAINSPRING

ower source for all watches (except those with battery- ors to spring-driven clocks in Italian documents of the 15thve been the home of the earliest portable timekeepers.

MAINTAINING POWER

ing whilst it is being wound. John Harrison first applied it tohe fusee and was gradually adopted (not necessarily on the mostgressed.

MASSEY, Edward

lever escapement, devised in the second decade of the 19thThere were five types, all adopting a drum-shaped roller with

sc with the pin standing on it. In the Massey I the pin is notherefore forms a pinion with only one leaf . The Massey III (theutrigger projecting from one end of the roller.

MEAN TIME

d, minute, hour etc. ± are of the same length throughout thee of the sun's time, by which the length of a 24-hour periodsured by a constant-rate timekeeper. In the 18th century,between solar time and mean time throughout the year, so that

MERLIN, Joseph

a timekeeper wound by the opening and shutting of a roomir¶ after him in the English of 200 years ago).

MOON HAND

MONTGOMERY DIAL

ures; an American fashion of the period 1890-1920.



MONTRE

trer , µto show¶) and the English names seem to contain the idea of y be connected with the fact that early public clocks seem to

the earliest examples had no dials at all, while 16th-centuryble clocks from which they developed, were therefore the first

MOTION WORK

n, fitted between the front plate and the dial of a watch to link thels are loosely fitted (one being located by the cannon pinion andnently removed for any reason the motion wheels are almost

MOVEMENT ers of movements survive without their cases, which haven remain in working order and can provide an easy means for theescapement types or other special areas of interest.

MUDGE, Thomas

orge Graham; inventor of the lever escapement (in a watch57); early contributor to the development of the c hronometer ;

MUSIC

e subject of an extended thesis. Hans Leo Hassler or Haslera chiming watch, was also a distinguished composer whole to Germany; he made a number of musical automata.Mell (fl. 1655-75), clockmaker of London, was leader of Kingusical watches and clocks for which Handel wrote ander on the bass viol and developed an idiosyncratic theory on the, Pierre Auguste Caron (1732-1799), watchmaker andsame with Pierre de Beaumarchais, author of the plays Le Barbier

i and Mozart operas are based.

NORTON, Eardley

y King George III and Catherine of Russia; probably thestory, Breguet not excepted. These are generally Swiss andns such as the single-footed cock , but they betray themselvesles in the dial. On Norton's death his business was taken overancestor of J. R. R. Tolkien.

OIGNON



se very deep calibre gave it a bulbous shape, the source of thehis is hollow and the winding-square projects through it in the

OIL SINK a pivot comes through the plate. This serves to retain oil and

he plate. Oil-sinks were invented in about 1720 by Henry

ORMSKIRK

m Liverpool , where there was a substantial colony of ivalent of Le Locle or Chaux-de-Fonds in Switzerland. Thefre's escapement.

OVERCOIL

f a hairspring by bending its outermost coil inwards and upwardsence of the spring. Breguet invented it and it is often called after

PAIR CASE

80 to 1820 (also used in Europe, but less exclusively). Thetes the crystal and pendant and (in Britain) is pierced at the

y separate outer case with openings for the crystal and pendant,ter) engine-turning. The outer case has to be removed for

lar case but was still fitted at times until about 1890, the Scots

PALLET

rtain escapements like the lever escapement and some types of to engage with the escape-w heel for the purpose of either

here are usually two pallets, one for each operation; they maye specifically designed to do one or the other ( spring detent ).

PARACHUTE

gainst lateral shocks by mounting each of its pivots in a springyple.

PASSING-SPRING

mponent (e.g. escape-wheel and balance) to pass each otherstructs the wheel on the return swing of the balance. This ist is achieved by making the passing-spring (which carries the



y weak but mounting a stronger spring alongside it, so that the balance encounters the passing-springg one way but meets both on its return, pushing the stronger spring with its locking-pallet into the path

eel teeth.

PENDANT

, ending in a cross-piece on which the bow is hinged.

PENDULUM WATCH

er descriptions of the late 17th century ± too often to beI suspect that, because the pendulum and the balance-spring ime and were perhaps invented or at least applied by the sameer to the latter.

PERPETUELLE the motions of a weight that swings round under the influencedifferent positions. The principle was known in the eighteenth

PERRON ESCAPEMENT placed on the lever by pins and the escape-wheel teeth areted by Perron of Geneva in 1798, applied by G. F. Roskopf s, and still found in some cheap 20th-century watches.


PILLAR

PINCHBECK, C

t hree-quarter-plate movement. Until about 1790 pillars were of nal in cross-section; afterwards they were cylindrical.

of the gold-like alloy (a form of brass) which bears his name.

PINION

e and generally used to transmit the drive between that wheelr eight µleaves¶, as their teeth are called.



PIN SETTING that a push-pin is used to disengage the hands from the train

PIROUETTE

d therefore the momentum) of the balance-wheel in a verge ngages with a vertical wheel of contrate form; the pallets are on

PIVOT

ne of the plates (usually, since the late 1800s, with a jewel bye and pivots often break, especially at the outer end of the

PIVOTED DETENT

pallets mounted on the rim of the balance-wheel itself interactetent) to achieve locking.

PLATE

with a number of holes to receive the pivots of a watch'ss, separated by pillars, and most of the movement wase which led directly to the modern layout with only one plate,

POKER HAND

, slim and tapered, with a touch of ornament near each end;

PORCELAIN

actually enamel .

POSITION ERROR in different positions. This is most often encountered inr not at all when placed upright or dial downwards, usuallyle of the cock is out of true; but it can occur on a smaller scaleit is a result of imperfectly balanced components or imprecisere often tested by their makers in different positions, and in

y well be recorded on the movement with some such notation as



POTENCE

t one end of an arbor . Bridge, cock and potence are overlappingck is generally used only of the bracket over the balance-wheel,d to the top plate and potence where it is mounted on the bottom

PRIVATE LABEL

r a retailer, whose name appears on the movement instead of ng of their own amongst collectors.

PUMP-WIND

rate a lever mounted on the bottom plate, acting on a ratchet,ding, this lent itself readily to use in conjunction with aritain, but it never became popular.

PURITAN WATCH

esign, precursor of the classic pocket-watch as we still know itgold case. So called in allusion to the austere religious

nd politically influential at the time.

QUARE, Daniel

of the repeater . Together with Tompion, Quare deserves a large's leader in horological matters throughout the 18th century.

QUARTER REPEATER

ur by striking the hour itself on one gong followed by one, two orond.

QUATRE

atre rubis (four jewels); this is the absolute minimum number inff is jewelled.

RACK-LEVER

l in 1791, using a principle outlined by Jean Hautefeuille in thethe inner end of the lever carries a toothed quadrant whichrtain vogue in England between about 1810 and 1825 and is



RAILROAD WATCH

ssarily actually applied as such, but designed and adjusted toWatches marked µChemin de Fer¶ or µRailway Time Keeper¶ beginwatch is an American phenomenon. It reached its height in theproduced specifications for watchmakers, laying down not onlyber of jewels (minimum 19 from 1920 onward) and even materials

ed scratches and because they harboured condensationse of the manufacturers' habit of offering different levels of finishingh railroad and non-railroad grades, and the dividing line betweene Hamilton company specialised in railroad watchesmetimes accounted the summit of the genre.

RAMSAY. David

ance and appointed clockmaker to King James I in 1613. Heincorporation in 1631. He was a prolific inventor in several

e-dyeing. He plays a significant part in Sir Walter Scott's novelero.

RATE

expressed as an average. Thus an early chronometer mightconds a week, and this would be taken as read in judging itserially from this rate it could be regarded as virtually perfecte compensated for by calculation.

thout qualification, to a watch's standard of performance; ³it hasood time´.

RECOIL

scape-wheel when it meets the pallet responsible for locking.movement of the controller; but sometimes it is allowed for

rocess secure (see draw ). This is true, for example, of the lever ts recoil from affecting the balance.

REGULATOR

ring by sliding the curb-pins, which lightly restrain it close to itsbalance-spring watches used the Barrow regulator, which1680 by the Tompion regulator and then, a century or so later, byey and has remained in use every since.

REMONTOIR

en constitutes a bitter disappointment to collectors who believem described in the next entry. In fact, it is merely French for

REMONTOIRE



nly in chronometers and first-class watches, for preventing theating a loss of pace at the balance. (The fusee cannot do thislave drive-spring, wound automatically at very short intervalspring; it is this slave spring which powers the escapement, the

Thus the watch µruns down¶ and is automatically re-woundum of the balance to carry it over the tiny loss of power, which

REPEATER

nd often the quarter-hours as well) when a plunger or slider isbetween the dial and the front plate, so that it adds very little touse the repeater never has to strike more than 15 times (12

6 times for a 24-hour clock-watc h ), so that only a smallg a chain. Daniel Quare invented the repeater in about 1680.

REVERSING PINION

et watch to be moved without disturbing its running. (Movingsome very odd consequences, especially if they are moved

ds in this situation.) It is found from about 1880 onwards andferred term in the U.S.A.

ROLLER

ever watch. The side that faces towards the lever (when therd of this stands the impulse-pin (a peg made of ruby), which

ROSKOPF, G. F.

x-de-Fonds, Switzerland, and set up a factory to produce ahad previously been possible. He did this by applyingtrain, which had only three wheels. The escapement was of in 1868.

RUBI

ench and Swiss watches, the jewels tend to be described aswels¶).

RUBY

amethyst and aquamarine have also been applied.




SAFETY PINION

SAFETY ROLLER

n the roller which carries the impulse-pin, and with a curved

SAVAGE ESCAPEMENT

oller (for locking) and a third on the lever itself, engaging in ated by George Savage, a Yorkshire watchmaker who

SELF-WINDING WATCH

SETTING

lance so that it fails to bridge the gap between one impulse andn the wearer's part; if this turns the body of the watch in thewill for a vital instant be motionless in relation to its immediatefatally upset.

SET-UP

mainspring, so that it never falls completely slack even whenr of the barrel . Until about 1780 set-up was adjusted by meansing with a wheel fitted to a squared section of the arbor and turnedtchet-wheel hidden behind the dial (or occasionally, in the earlye of set-up can be critical to a watch's rate.

SIDE LEVER

l in Britain from about 1815 to 1910; the lever is positionedape-wheel and the balance.

SINGLE SUNK

he remainder of the dial itself being flush. This arrangementin and America from about 1860. Swiss dial-makers achievedby cutting out a hole and soldering a separate panel into place



SKELETON DIAL

out to reveal the movement behind (the front plate being

SPADE HAND

µspade¶, but somewhat narrower; widely used in the period

SPIRAL BREGUET

French term for an overcoil balance-spring; often stamped or

SPRING DETENT

ughout the 19th century, invented by either Arnold or Earnshaw ince-staff comes up against a light flat spring; on the anti-n the spring is pressed against another stronger one

ck and the escape-wheel moves, giving impulse through one

STEADY PIN

a hole in the plate and so ensuring that the bridge etc. is

STOP-WORK

The chain, as it approaches the bottom plate, lifts a spring-he fusee-cone; when these two meet, the winding-gear israin (and therefore the hands).

STRAIGHT-LINE LEVER

what confusingly so called, since the lever does not form aname results from the fact that the arbors of the balance, leverually older than the side or English lever which was predominant infrom the rack-lever .

SUBSIDIARY SECONDSDIAL

k position and (from about 1860) recessed to increase thels are rare until about 1810, although there is an example by



om the 1680s.

SULLY, Henry

France, inventor of the oil-sink and early experimenter with the

longitude.

SUPPLEMENTARY ARC

and after its period of interaction with the train.

SWEEP SECOND HAND

eps the entire surface of the dial. The expression is oftenas Mudge's first lever watch (1759) seems to be the earliest

SWITZERLAND

field of watchmaking, came very late to that distinction.direct ancestor of the great Abraham Louis, was already at workwiss were mainly noted for enamelled cases (a Genevaarkets, and inferior forgeries or imitations of English work. It is

in 18th-century horology were of Swiss origin although theyh Emery (a lever pioneer) in London. By about 1800 the Swissof the market ( J apy 's volume-production techniques, forwatches), but at the same time the two Jaquet-Droz, father andy about 1850 the Swiss had generally adopted the barred layoutngly followed even by those who professed to despise their

tzerland finally cast off her reputation for second-class work and, supported by rigorous testing procedures.

TACT, Montre à

means of telling the time from a watch by touch alone. The wideknob at each hour. An extra hand, fitted outside the crystal ,

t driven by the train, but when it reaches a position directly overtherefore be used in conjunction with the chapter-ring to tell the

THIRD WHEEL

w heel . In a full-plate watch it is usually recessed into the front plate.

THIRTY-TOOTHESCAPE WHEEL

omitted and the escape-wheel, which takes its place andusual fifteen, so that the hand makes a complete circle in fifteen-lever ) can be recognised at once because the seconds dial is



10-15.

THREE-QUARTER PLATE

ut cut away at one side to make room for the balance-wheel,

ng beyond it. This style was introduced by British makers inlimmer movements. For much of the 19th century it was oftend precision.

TIMING SCREW

horizontally in the rim of a compensated balance. Adjustingay help to correct position errors; adjusting them uniformly

lters its speed of oscillation, affecting the rate of the watch.alances.

TIPSY KEY ated a ratchet so that if turned the wrong way it revolved

TOBIAS

lised in pretentious but well-made products for the risingthe London Docks, from 1794 onwards; Michael Isaaccipal exponents of the rack-lever . From about 1850 the nametheir barred layout and engraved cuvettes and by the (probably

TOMPION, Thomas

than anyone else established the supremacy of Englishooke and maker of the earliest English balance-spring watches;hand. In the literature of his day his name appears as a bywordhe 1800s or µRolex¶ today.

TOP PLATE

TOURBILLON

. The balance-wheel and escape-wheel are mounted on aakes a complete turn every sixty seconds; thus any imbalanceherwise affect the rate of the watch in some orientations, canre being cancelled out by the change in alignment. Latersort to so very short a cycle; the karrusel , a later development



TRACK

econds, usually consisting of radial strokes between a pair of the latter are only guides, drawn as faintly as possible. Dots

es found between about 1760 and 1800.

TRAIN

the drive from the barrel (or fusee cone) to the controller. Itw heel , fourt h w heel and escape-w heel ; each of these carries at.

4,400 train¶, it indicates the number of beats made by thehour. 14,400 (four per second) is the usual figure for a largeAmerican watches the figure is 18,000 (five per second).

TRIPPING

in only one direction, such as the duplex and spring detent .ntroller and deliver impulse twice in one cycle, resulting in a

TURKISH MARKET

n the Ottoman empire developed a liking for European watches,akers; later on (from about 1800) the Swiss gained possession

s with pirated English names, a practice which lasted throughoutgnised by their c hapter-rings; the numerals consist mostly of s represented by a circle. The watches are often very ornate,ple cases. Most disconcertingly for the modern collector, they, deep in calibre and with floridly-shaped bows andwhich is often a commonplace Swiss ébauc he of barred type, to


UP-AND-DOWN

INDICATOR up, usually working on a subsidiary dial placed below the 12

UNITED STATES

e hampered by a want of metallurgical skills and raw materials;me of the earliest American clocks. Many early µwatchmakers¶ , the American Watch Company (afterwards W alt ham ), with



s technical supervisor, was producing watches of a type already distinctive (based on Liverpool hout fusees ), using efficient machine-based methods inspired partly by Swiss models and partly bys in American small-arms manufacture. Several more substantial manufacturers, such as Elgin,fterwards Hamilton ), E. Howard, the Illinois and New York companies, and Cornell in far-off Santheir factories between 1858 and 1875. By 1900 the stringent and specific demands of the great

s were shaping the nature of the railroad watc h, and the largest firms were producing hundreds of ches annually.

esign tended to be advanced but not innovative; few new or unfamiliar devices appeared (the cheapny's astonishing flirtation with the duplex escapement in the 1880s is an exception), but it wasnsplanted such things as overcoil hairsprings, compensated balances and the general jewelling of the realm of the exotic to that of the commonplace. In appearance, watches of 18 size or larger (seewere often full-plates until after 1900, while smaller calibres adopted a compromise barred design withng several wheels instead of only one ² a pattern which became almost universal in the wrist-watchhe U.S.A. is the use of grade-names; in addition to or instead of the manufacturer, a watch might beame of a company director or supporter (Waltham's µP. S. Bartlett¶, Elgin's µB. W. Raymond¶), a

riotic phrase (µLadies' Stem Wind¶, µNative Son¶) or the name of a historical character (New York's µJohnen's µMolly Stark¶). A single model (for the U. S. manufacturers also adopted model designations)veral different grades each distinguished by an individual name.

VERGE d (probably before 1300) for large wrought-iron church clocks-century French watches an inch or less in diameter. Vergefast; Captain Cuttle's watch in Dombey and Son ² ³Put it backowards the arternoon, and it's a watch that'll do you credit´ ² isbered that in this escapement the contact between pallets nally violent and conducive to wear. See Escapements for more

VERGE-STAFF

f a verge movement, with the crown-w heel at its inner end and anut half-way along its length. In English and Dutch watches therench and Swiss makers from about 1750 onwards preferred anstable by means of two small steel screws whose heads facean English watch.

VIRGULE

he 1750s by Jean André Lepaute and refined by Lépine. The jects from it on the side where the escape-wheel teeth emerge

an enhanced impulse, but only on alternate swings of theto the period 1780-1820.

WALTHAM

set up in 1849-50 by Aaron Dennison in partnership with Edwardral reincarnations, including Appleton, Tracy & Co. (1857; thename on much later Waltham watches, so that very few of theCivil War period). The Waltham name iself dates officially fromrels, screwed-in movements, jewelled train-wheels andtyle for the entire industry. The 1883 model, ( side-lever and

Waltham responded effectively to the demand for railroad of the Swiss wrist-watch. The independent company ceased



WATERBURY

nded as clockmakers in 1843 and connected with the pioneer

The Waterbury name dates from 1857 and watchmaking beganches (as they still do, under the name µTimex¶) but made aduplex series in the 1880s.

WINDING SQUARE

to receive a key, in a key-wound watch.

WINGED COCK

or stylised wings) on either side of the circular table at the point

m about 1710 to 1750.

ZECH, Jakob

ecisely datable portable table clock (effectively a very large1525 and has a wrought-iron verge movement with fusee, hour

ing once a year, and a simple striking mechanism.

a brief glossary of technical terms

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