Terminology of Timepieces
Watches
Movement - the heart of a watch, the timekeeping mechanism. Has gears, a balance wheel and moving parts (quartz watches do not have movements.)
Jewels - Synthetic sapphires or rubies used to reduce friction in mechanical watches. They add to the accuracy and dependability of watches. Usually there are 15 or 17 jewels in a watch, but those with complications may have as many as 26.
Face or Dial - The area of a watch that displays the numbers, minutes and hour markers that tell the time.
Hands - Usually metal, they indicate the hour, minutes and seconds
Watchcase - houses and protects the movement. Watchcases can be made of gold, silver, steel, plastic, silver-plated metal, aluminum, platinum, or titanium alloys.
Crown - set on the side of a watch, a round button that is usually ribbed, used to set and wind a watch
Crystal - protective lens covering the watch face, made of clear sapphire glass, plastic, or mineral glass
Bezel - metal rim surrounding the face and holding the watch crystal
Incabloc - a mechanism in the watch that is shaped like a cloverleaf and shields the movement; works like a shock absorber
Caliber - the size of a watch movement
Numbers - watches use Arabic numerals, Roman numerals, sticks, or a combination of these. Some have no numbers at all.
Ebauches - the most basic watch movement, bought by watch manufacturers who then add their own refinements and complications
Watch Complications
Complications are, essentially, mechanically sophisticated movements. The best known include:
Chronograph - a watch whose second hand functions as a stopwatch
Split-Second Chronograph - a variation on the chronograph, it overlays the chronograph hand with another second hand so that the user can clock intermediate times
Date Indication - using a hand or a rotating disk, shows the date
Day Indication - shown by a hand or disk
Moon Phase - shows the number of days since the last new moon, usually through a window on the dial
Repeater - a watch that has an integral chime.
Automatic Wind - since a wristwatch is worn on a part of the body that constantly moves, it can use this mechanism that incorporates a pendulum. The watch will wind itself as long as the wearer moves.
Clocks
Movement - as with a watch, the movement is the set of mechanical parts that makes the hands go around the face of the clock. Clocks have two types of movements. Weight-driven clocks are powered by the dropping of weights while spring-driven clocks are propelled by the uncoiling of springs.
In both types of movements a series of intermeshing gears revolves and moves the hands of the clock around the dial. How precisely they move is regulated by the escapement, a mechanism that allows the power trapped in the weights or the spring to escape in a controlled fashion. Tension is released as the spring unwinds or the weight drops. The "tick tock" sound we associate with clocks is caused by the movement of the escapement.
Striking Clock - a clock that strikes or chimes the hours on a bell or gong
Case - houses and protects the clock movement
Tallcase or Longcase - clocks housed in tall cases made to stand upright on the floor. "Grandfather clock"
Bracket Clock - European, a smaller version of the longcase clock, intended to stand on a piece of furniture or on a wall bracket (usually matching the clock case). English bracket clocks often had a carrying handle on top
Shelf Clock - American, similar to the bracket clock
Carriage Clock - smaller clocks (made in several sizes) with a handle that could be used to carry the clock from place to place.
