====== Repetition ======
{{wst>image_l|Viertelrepetition|[[Pocket watch]] with **quarter repetition**}}
Watch function ([[complication]])

(Also //Repetition watch, repeater//)

===== Definition =====
**Repetition** means the repeated playing of an acoustic signal at a [[clock]] or watch. In mechanical watches this requires a special, expensive additional mechanism ([[complication]]), the repetition carillion (see below).

Repetitions are well known by the sounds played by church tower clocks (Big Ben, for instance).

Essentially there are repetitions of the following type:
  * Hour repetition (also: striking hours)
  * Quarter repetition (French: //Repetition à quarts//)
  * Half quarter or 7½-minutes repetition, also one-eighth repetition
  * Five minutes repetition
  * Minutes repetition

Due to the high mechanical effort repetitions are regarded as one of the most value-adding [[complication]]s in a mechanical watch.

===== Repetition carillion =====
{{wst>image_cr|Jaeger-LeCoultre|Hybris Mechanica à Grande Sonnerie|260px}}

To represent the time acoustically, the [[carillion]] (or [[chime movement]]) needs power. This it activated by the operation of a [[slider]] or [[pusher]] at the case edge. At the same time, this process also triggers the percussion mechanism. If pusher or slide have not been moved to the stop, simple repeaters beat the time incompletely. In fine constructions this is prevented by a so-called //all-or-nothing switch//. They then repeat properly or not at all.

===== Strike sequences =====

  * **Three-quarter strike:** \\ All quarters are stroken, whereas at the fourth quarter the full hour is beaten on a large bell.
  * **Petite Sonnerie:** \\ Here the quarter-hours are indicated --- possibly with a double strike on two bells. On the full hour the number of hours is beaten on a larger bell, without the quarters.
  * **Grande Sonnerie:** \\ On each quarter of an hour, first the full hour is given on a larger bell, and then the quarters (usually with a double hit) --- but not on the full hour; this is beaten without the quarters.

===== The most famous melodies =====
==== Westminster chime ====
This chime originally comes from the University Church in Cambridge and is taken from a composition by G.F. Handel. However, this short melody has become world famous as the hour strike of the bell tower Big Ben at the Parliament in London.

==== Whittington ====
Named after the important mayor of London Dick Whittington, who in a difficult hour allegedly heard his appointment as mayor in this sequence of sounds.

==== St. Michael ====
This chime is named after St. Michael's Church in Charleston, South Carolina. During the War of Independence and the American Civil War, the bells of this church came to harm several times, were restored in London, and finally [[1867]] were ceremonially reinstalled.

{{tag>Terms}}