striking. On the shaft of the minute hand (not shown), which rotates once per hour, there is a projection. As the change of the hour approaches, this projection slowly lifts the release lever, allowing the rack to fall until its point rests on the snail (N). The amount the rack can fall, and thus the number of strikes, is determined by the position of the snail. Exactly on the hour the striking train (G, H, K) is released and begins to turn. As it turns, the pins (G) repeatedly lift the hammer (F) and allow it to drop, ringing the gong (E). The gear ratios are arranged so that the gear wheel (H) makes one revolution each strike. A small pin (S) on this wheel engages the rack teeth, lifting the rack up by one tooth each turn. When the rack reaches the end of its teeth it stops the striking train from turning (using a mechanism not shown in the diagram, in such a way that gear (H) is held stationary with the pin (S) not engaging the rack, so that the rack is able to fall freely again on the next hour). So the number of strikes is equal to the number of teeth of the rack which are used, which depends on the position of the snail. Types of striking clocks Specialized types of striking clocks: Chiming clock – Strikes on the hours and chimes on the quarter hours, often playing fragments of a tune such as Westminster Quarters. Repeater – a striking clock which can repeat the strikes at the push of a lever, for telling the time in the dark. Musical clock – plays tunes on a music box in addition to counting the time Automaton clock – with mechanically animated figures that periodically perform various displays, usually as a part of the clock striking the hours. Cuckoo clock – a specific type of automaton clock which originated in Germany, which displays an animated bird and plays imitation birdcalls in addition to striking on a bell or gong. Ship's bell clock – strikes the ship's bells instead of the hours. Some quartz clocks also contain speakers and sound chips that electronically imitate the sounds of a chiming or striking clock. Other quartz striking clocks use electrical power to strike bells or gongs. See also Alarm clock Repeater watches (horology) St. Michael's chimes Thirteenth stroke of