Watch glossary: C (part1)

CABOCHON
Any kind of precious stone, such as sapphire, ruby or emerald, uncut and only polished, generally of a half-spherical shape, mainly used as an ornament of the winding crown or certain elements of the case.
CALENDAR, ANNUAL
An intermediate complication between a simple calendar and a perpetual calendar. This feature displays all the months with 30 or 31 days correctly, but needs a manual correction at the end of February. Generally, date, day of the week and month, or only day and month are displayed on the dial.
CALENDAR, FULL
Displaying date, day of the week and month on the dial, but needing a manual correction at the end of a month with less than 31 days. It is often combined with the moonphase.
CALENDAR, PERPETUAL
This is the most complex horology complication related to the calendar feature, as it indicates the date, day, month and leap year and does not need manual corrections until the year 2100 (when the leap year will be ignored).
CALIBER
Originally it indicated only the size of a movement, but now this indication defines a specific movement type and shape (e.g. round caliber) and combines it with the constructor's name and identification number. Therefore the caliber identifies the movement.
CANNON
An element in the shape of a hollow cylinder, sometimes also called pipe or bush, for instance the pipe of the hour wheel bearing the hour hand.
CARAT (KARAT)
Unit of gold fineness (and gemstone weight). Pure gold is 24k. 18k gold is 75% pure.
CAROUSEL
Device similar to the tourbillon, but with the carriage not driven by the fourth wheel, but by the third wheel.
CARRIAGE or TOURBILLON CARRIAGE
Rotating frame of a tourbillon device, carrying the balance and escapement. This structural element is essential for a perfect balance of the whole system and its stability, in spite of its reduced weight. As today's tourbillon carriages make a rotation per minute, errors of rate in the vertical position are eliminated. Because of the widespread use of transparent dials, carriages became elements of aesthetic attractiveness.
CASE
Container housing and protecting the movement, usually made up of three parts: middle, bezel, and back.
CENTER SECOND HAND, see sweep second hand.
CENTER-WHEEL
The minute wheel in a going-train.
CHAMPLEVé
Hand-made treatment of the dial or case surface. The pattern is obtained by hollowing a metal sheet with a graver and subsequently filling the hollows with enamel.
CHAPTER-RING
Hour-circle, i.e. the hour numerals arranged on a dial.
CHIME
Striking-work equipped with a set of bells that may be capable of playing a complete melody. A watch provided with such a feature is called chiming watch.
CHRONOGRAPH
A watch that includes a built-in stopwatch function, i.e. a timer that can be started and stopped to time an event. There are many variations of the chronograph.
CHRONOMETER
A high-precision watch. According to the Swiss law, a manufacture may put the word "chronometer" on a model only after each individual piece has passed a series of tests and obtained a running bulletin and a chronometer certificate by an acknowledged Swiss control authority, such as the COSC.
CIRCULAR GRAINING
Superficial decoration applied to bridges, rotors and pillar-plates in the shape of numerous slightly superposed small grains, obtained by using a plain cutter and abrasives. Also called Pearlage or Pearling.
CLASP
The attachment used to connect the two ends of the watch bracelet or strap around the wrist.
- Deployment Buckle - A three-folding enclosure, which secures the two ends of the bracelet and allows enough room for placing the watch on the wrist when fully deployed. When closed, the buckle covers the two-piece folding mechanism
- Hook Lock - Two separate units each fitting on either end of the bracelet which allows the watch to be laid out. One end of the closure hooks onto the other to secure the two ends of the bracelet.
- Jeweler's Clasp - A closure that is generally used on better bracelets. Also allows it to lie flat.
- Sliding Clasp - Also a hook type method but allows for easy sizing of the bracelet by sliding up.
- Twist Lock - A closure similar to Jeweler's Clasp used on ladies jewelry bracelets.
CLOISONNé
A kind of enamel work - mainly used for the decoration of dials - in which the outlines of the drawing are formed by thin metal wires. The colored enamel fills the hollows formed in this way. After oven firing, the surface is smoothed until the gold threads appear again.
CLOUS DE PARIS
Decoration of metal parts characterized by numerous small pyramids.