History of Pendulum Clocks: Parts and Complications

Until the 19^{th century, mechanical pendulum clocks were very expensive because they were handmade by individual craftsmen. An} authentic German cuckoo clock, for example, was handcrafted by artisans and clockmakers in the Black Forest region of Germany. To own a handmade clock was to show the world that you were a person of wealth. The industrial revolution changed all of that. The home pendulum clock became a means to organize daily life and businesses used them to schedule work. For nearly 300 years, mechanical clocks were the standard timekeepers.



Parts of a Mechanical Clock
All mechanical clocks have five basic parts Power source – This involves a mainspring or pulley being turned by a weight on a cord or chain.
Gear – Controls the pendulum power and speed
Escapement - Keeps the pendulum swinging using precise impulses
Pendulum – The weight on a rod
Indicator – Known as the clock face. It's the outward record of the escapement rotation

Basic pendulum clocks are used for timekeeping but what many don't realize is that more elaborate pendulum clocks had additional functions called complications. These features went beyond simply displaying the time on the clock face and ranged from simple to complex to rare.
Striking Train – If you've heard a clock strike 12 times at noon that is the simple striking chain complication where the number of chimes equals the hour. More elaborate complications strike every 15 minutes and could even include music.

Moon phase dial – The moon, or lunar, phase is a very accurate lunar calendar that showed the phases of the moon. This complication goes back to about the 1500's. Street and road lighting at night were very rare. If someone wanted to have guests over in the evening, they needed to know when there would have enough moonlight to light the streets. So the creation of the moon phase dial helped to predict when there would be sufficient moonlight as well as when the tides would rise and fall.

Equation of Time – This is an extremely rare complication that measured the difference between the position of the sun and clock time, which varied throughout the year by as much as sixteen minutes more and less. One of the oldest examples of this kind of solar pendulum clock dates back to the early 18th century and ^{resides in the British Museum.}


The history of pendulum clocks is an extensive one and it's amazing how something so simple could revolutionize the perception and use of time.