A cuckoo clock is typically pendulum-regulated, and strikes the hours with a sound like a common cuckoo’ call and often has a mechanical cuckoo that emerges with each note. The mechanism to produce the cuckoo call was installed in almost every kind of cuckoo clock since the middle of the 18th century and has remained almost without variation, until the present day.
Most cuckoo clocks are made in a traditional style (also known as “carved” or “chalet”) to hang on a wall. The traditional style is a hand carved wooden case that is decorated with carved leaves and animals.
They have an automated cuckoo bird that appears through a small trap door while the clock is striking. The bird is often made to move as the clock strikes, typically by means of an arm that lifts the back of the carving.
There are two kinds of movements: one-day (30-hour) and eight-day clockworks.
Some have musical devices, and play a tune on a Swiss music box after striking the hours and half-hours. Usually the melody sounds only at full hours in eight-day clocks and both at full and half hours in the one-day timepieces.
Musical cuckoo clocks frequently have other automations which move when the music box plays. Today’s cuckoo clocks are almost always weight driven, though a very few are spring driven.
The weights are made of cast iron in a pine cone shape and the “cuc-koo” sound is created by two tiny gedackt (pipes) in the clock, with bellows attached to their tops. The clock’s movement activates the bellows to send a puff of air into each pipe alternately when the timekeeper strikes.
In recent years, quartz battery-powered cuckoo clocks have become available.
As with their mechanical counterparts, the cuckoo bird emerges from its enclosure and moves up and down, but on the quartz timepieces it also flaps its wings and opens its beak while it sings.
During the call the double doors open and the cuckoo emerges as usual, but only on the full hour, and they do not have a gong wire chime. The movement of the cuckoo in such clocks is regulated by an electromagnet that pulses on and off, attracting a weight, that acts as a fulcrum, connected to the tail of the plastic cuckoo bird, thus moving the bird up and down in his enclosure.
Instead of the call being reproduced by the traditional bellows, it is a digital recording of a cuckoo calling in the wild (with a corresponding echo). The cuckoo call is usually accompanied by the sound of a waterfall and other birds in the background.
In musical quartz clocks, the hourly chime is followed by the replay of one of twelve popular melodies (one for each hour). Some musical quartz clocks also reproduce many of the popular automations found on mechanical musical clocks, such as beer drinkers, wood choppers, jumping deer, and angry wives beating lazy husbands.
Uniquely, quartz cuckoo clocks often include a sensor, so that when the lights are turned off at night they automatically silence the hourly chime. Other quartz cuckoo clocks are pre-programmed not to strike between a set of pre-determined hours.
Whether this is controlled by a light sensor or pre-programmed, the function is referred to as a ‘night silence’ feature.
On quartz clocks the weights are conventionally cast in the shape of Aleppo pine cones made of plastic rather than iron, as are as the cuckoo bird and clock hands. The pendulum bob is often another carved leaf. Here, the weights and pendulum are purely ornamental as the clock is driven by battery power. As with mechanical cuckoo clocks, the dial is usually small, and typically marked with Roman numerals.
Several unusually large cuckoo clocks have been built and installed in different cities of the world with the aim of attracting visitors, as part of publicity of a cuckoo clock shop, or to serve as a landmark for the community and town.
Some have been awarded with the title of “World’s Largest Cuckoo Clock” by the Guinness World Records.
Cuckoo clocks can be inspired by contemporary decorative styles as well. These modern timekeepers are characterized by functional, schematic and minimalist aesthetics.
There have been timepieces with an automated bird since antiquity. The first one is credited to the Greek mathematician, Ctesibius of Alexandria (ca.285-222 BC), who in the 2nd century BC used water to sound a whistle and make a model owl move.