CLOCKMAKERS COMPANY. The Worshipful Company of Clockmakers was granted its Royal Charter in 1631, with David Ramsay as its first Master. Prior to its incorporation, the craft of clock and watchmaking was controlled by the Blacksmiths' Company, and it would seem that boys were apprenticed as Blacksmiths in the earlier years. In the City of London apprentices were admitted through the Guilds, and after they had served their term they were granted the freedom of the craft. The Clockmakers' Company had the right to regulate the manner, order and form in which the craft should be conducted within the realm of England. It had powers to make laws and ordinances for all persons using the Art within a ten-mile radius of the City of London and had wide powers touching the 'Trade, Art or Mystery'.
The Company had the right to make a general search and view all productions made in this country or brought in from abroad: it had powers to seize and to destroy unworthy work or cause it to be amended. None but admitted members might sell their wares within the City or ten miles thereof. An apprentice was bound for seven years and, after admittance as a Freeman, served a further two years as journeyman and then produced his masterpiece before being admitted as a workmaster. A Brother was allowed to engage only one apprentice, a Warden or Assistant Warden two only.

CLOCK - WATCH. A watch which strikes the hours at the hours. Not to be confused with a repeating watch. Clock-watches were made from the earliest period.

CLOISONNÉ. Divided into 'cloisons' or compartments by means of flat metal wires, forming a design in outline on a flat or curved surface. In cloisonne enamel, the partitions are filled with coloured enamels, and then fired. After polishing, the metal strips show off the design inlaid in the enamel. The metal used is mostly gold.

CLUB-FOOT VERGE. A frictional-rest dead-beat escapement, derivative of that invented by Debaufre circa 1704. Sometimes referred to as the 'dead-beat verge', or 'Ormskirk escapement,' after the town in Lancashire where watches with this escapement were made in the early 19th century.

CLUB - TOOTHED LEVER. A lever escapement with the form of escape wheel usually found in continental lever watches, as opposed to the English form of pointed-tooth escape wheel. In the club-tooth escape wheel the 'lift' is divided between the pallet stones and the impulse faces of the teeth. In the English form the impulse is taken entirely by the pallet stones.

COCK. A bracket, one end of which is fixed to the movement plate, the other end supporting the pivot of a wheel. The balance cock supports the top pivot of the balance staff and is mounted on the top plate of the watch movement. The earliest form was a simple S-shaped support. The cock was gradually given greater and more elaborate decoration to both foot and table, the former being that part of the cock which is fixed to the plate and the latter that part over the balance and providing the bearing for the top pivot of the balance staff. The English form of balance cock, as above described, is sometimes found on Dutch, German and Swiss watches of the early 18th century. Apart from this, the French and continental form of cock is round or oval with lateral lugs to take the fixing screws. In this form it is strictly speaking a bridge rather than a cock.
Both English and continental cocks underwent changes, the finest quality being found between about 1625 and the early 18th century. Balance cocks are a useful guide to dating a watch.

COLLET. A collar. Part of a cylindrical piece of metal of greater diameter to the rest. An example is the small ring of metal which is fitted friction-tight to the balance staff to secure the inner end of the balance spring. A 'hand collet' is a dome-shaped washer to render secure the fitting of the hands.

COLOURED GOLD. See TINTED GOLD.

COMPENSATED BALANCE. A watch or chronometer balance that compensates for the effects of heat or cold. Airy showed, in 1859, that a chronometer with an uncompensated brass balance and steel spring lost on its rate 6 11 seconds in 24 hours for each degree (Fahrenheit) rise in temperature. It was known in the 18th century that changes in temperature affected the rate, and during the last half of that century various attempts were made to combat it. Pierre Le Roy was the first to attempt compensation by means of the balance which culminated in the cut bimetallic balance of Thomas Earnshaw. The same form of balance, only slightly modified, is used in modern marine chronometers, though it has been superseded in modern watches by a metal alloy monometallic balance coupled with an alloyed balance spring which is unaltered by temperature changes. See BALANCE.

COMPENSATION CURB. A laminated bar (or bimetallic strip) composed of brass and steel fixed at one end and free at the other, the later end carrying the curb pins (q.v.). 1t was first employed by John Harrison. The effect of a rise or fall in temperature causes the strip to bend, thus moving the curb pins in relation to the balance spring. The more usual form of the strip is an elongated U with one curb pin fixed to the free end of the strip, which is caused to move away from (in cold) or closer to (in heat) the other pin, thus varying the play of the spring between the pins and roughly compensating the effects of temperature on the steel balance spring. The U form of compensation curb is associated with Breguet and was in fairly common use in France in the earlier part of the 19th century. It was fixed to the index (q.v.). See also SUGAR TONGS and 'S' BALANCE.

COMPLICATED WORK. A mechanism other than timekeeping - e.g. repeating, calendar work, chronograph work. La Vallee de Joux, Switzerland, became the centre for such work in the second half of the 19th century.

CONICAL PIVOT. A misleading term. 'Shoulderless pivot' would be more accurate. The pivot itself is straight, the 'shoulder' slightly conical. Breguet used conical (pointed) pivots to the balance staff of his lever watches. These give added strength, but they are not conducive to a close rate.

CONSULAR CASE. A double-bottom watch case fitted with a high rounded glass. Named in honour of Napoleon; at the time of their introduction he was Consul of France. The back of the case is hinged and when opened, a second back (or 'bottom') is revealed in which are the two holes for winding and hand-setting. The movement itself swings out from the front when the bezel is opened.

CONSTANT FORCE ESCAPEMENT. An escapement in which impulse is imparted by a spring which is itself tensioned by the going train. 'Constant' because the force or impulse delivered is unaffected by any irregularities arising from fluctuations in the power delivered by the mainspring. See also REMONTOIRE.

CONTRATE WHEEL. A wheel the teeth of which are at right angles to the plane of the wheel. In a watch with a verge escapement, it is the wheel which drives the escape wheel pinion.

CONVERSION. A watch is said to have been 'converted' if an escapement of one kind has been substituted for another. Thus a verge escapement may have been converted to a lever, and the escapement is a conversion.