History of Clocks

The history of the time telling device can be traced to antiquity. Vitruvius
reports that the ancient Egyptians used clepsydras, a time mechanism run by
flowing water. By the 9th century AD a mechanical timekeeper had been
developed that lacked only an escapement mechanism. There is a record that in
1176 Sens Cathedral installed a �horologe��the word still used in French for
large clocks. It is derived from the Greek hora meaning �hour� and legein
meaning �to tell. This word has led scholars to believe that these tower
clocks did not employ hands or dials, but �told� the time with audible
signals.

The earliest reasonably accurate clocks are the 13th century tower
clocks probably developed for (and perhaps by) monks in Northern Italy. These
were used to announce the canonical hours or intervals between set times of
prayer. Canonical hours differ in length, and varied as the times of sunrise
and sunset shifted.

The earliest table clocks that survive in any quantity are mid-16th century
ones from the metalworking towns of Nuremberg and Augsburg. These clocks have
only one hand. The dial between the hour markers is divided into four equal
parts making the clocks readable to the nearest 15 minutes.

The next major development in accuracy occurred in 1657 with the invention
of the pendulum clock. Galileo had the idea to use a swinging bob to propel
the motion of a time telling device earlier in the 17th century. Christian
Huygens, however, is usually credited as the inventor. He determined the
mathematical formula that related pendulum length to time (99.38 cm or 39.13
in for the one second movement) and had the first pendulum driven clock made.
In 1670, the English clockmaker William Clement created the anchor escapement,
an improvement over Huygens' crown escapement. Within just one generation,
minute hands and then second hands were added.

The excitement over the pendulum clock attracted the attention of designers
resulting in a proliferation of clock forms. Notably, the long case clock (aka
grandfather clock) was created to house the pendulum and works. The English
clockmaker William Clement, inventor of the anchor escapement, is credited
developing this form in 1670. It was also at this time that clock cases began
to be made of wood and clock faces to employ enamel.

A cuckoo clock is a clock, typically a pendulum clock, that strikes the hours
using small bellows and whistles that imitate the call of the Common Cuckoo
bird in addition to striking on a wire gong.

The design of a cuckoo clock is
now conventional. Most are made in the shape of a rustic birdhouse or chalet.
They hang on the wall, and are housed in wooden cases, frequently decorated
with carved leaves; sometimes deer and other animals are added. Most now have
an automaton of the bird that appears through a small trap door when the clock
is striking, and vanishes behind the door after the clock is done.

The bird is often made to move while the clock strikes, typically by means
of an arm that lifts the back of the carving. Some have musical movements, and
play a tune on a music box before striking the hours or half-hours. Musical
cuckoo clocks frequently have other automata that move when the music box
plays. The clocks are almost always weight driven; a very few cuckoo clocks
are spring driven.

In recent years, fake quartz battery powered cuckoo clocks have been sold;
these do not have genuine cuckoo bellows, and typically generate their
striking sounds electronically. The weights are conventionally cast in the
shape of pine cones. The pendulum bob is often another carved leaf. The dial
is small, and typically marked with Roman numerals.

The cuckoo clock was invented in the Black Forest town of Sch�nwald,
Germany, by Franz Ketterer in 1738. Ketterer designed the system of small
bellows and whistles that imitates the Cuckoo's call, and added them to a
standard Dutch clock. Later refinements of the design changed the clock's
shape to the familiar birdhouse or chalet. The centre of their production
continues to be in the Black Forest region of Germany, in the area of Triberg
and Neustadt. The cuckoo clock is often wrongly associated with Switzerland,
as in the movie The Third Man. This error is probably due to a story by Mark
Twain in which the hero depicts the Swiss town of Lucerne as the home of
cuckoo clocks.

A grandfather clock, also floor clock or long case clock, is a freestanding
clock with a pendulum held inside its own tower, commonly around 6-8 ft tall.
The tower often features elaborately carved wood at the head, surrounding the
clock face. The English clockmaker William Clement is credited with the
development of this form in 1670.

Over one hundred years ago there was a hotel known as the George Hotel that
was managed by two brothers named Jenkins. The hotel had a floor clock that
kept time very well.

One of the two brothers died, and the clock started to
lose time. Repair attempts were made, but they all failed. When the other
brother died at the age of 90, the clocked stopped running altogether, and was
never repaired in remembrance of the brothers.

Around 1875, Henry Work, a song writer, was staying at the George Hotel and
learned the story of the old floor clock. He decided to write a song about the
clock. The song became very popular and sold over a million copies.

The first part of the song goes: "Oh, my grandfather's clock was too tall
for the shelf, so it stood ninety years on the floor. It was taller by half
than the old man himself, though it weighed not a pennyweight more." After
this, people started calling floor clocks by the name grandfather clocks.

These articles are licensed under the "GNU�Free�Documentation�License".�
They use material from the Wikipedia articles; "Clock",
"Cuckoo_clock"
and�"Grandfather_clock".