A cuckoo clock is a clock, typically pendulum driven, that
strikes the hours using small bellows and whistles that imitate
the call of the Common Cuckoo in addition to striking a wire
gong. The mechanism to produce the cuckoo call was installed in
almost every kind of cuckoo clock since the middle of the
eighteenth century and has remained almost without variation
until the present. The design of a German cuckoo clock is now
conventional. Most are made in the shape of a rustic birdhouse
or chalet to hang on a wall. The wooden case is frequently
decorated with carved leaves and animal heads. Most now have an
automaton of the bird that appears through a small trap door
while the clock is striking. The bird is often made to move
while the clock strikes, typically by means of an arm that lifts
the back of the carving. There are two kind of movement: a one-
day movement and an eight-day movement. Some have musical
movements, and play a tune on a swiss music box after striking
the hours and/or half-hours. Musical Ge