Clocks are fascinating machines with an incredible history. The first clock was probably a stick stuck in the ground to form a simple sundial. Thousands of years later, this method of tracking time is still useful.

One of the earliest clocks developed was the water clock. Although water clocks have been built in many shapes, sizes and levels of complexity, they all share a common premise. A measured amount of water is placed in a vessel that has a hole in it. The size of the hole allows the water to run out of the container at a certain speed. The amount of water and size of the hole are integrated so that a certain period of time has elapsed when all the water has run out of the vessel. Water clocks were the most accurate time measuring devices for thousands of years.

It wasn’t until the invention of the pendulum clock in the 17^th century that the accuracy of a time-keeping invention surpassed the water clock. Pendulums are still used in grandfather clocks and they are responsible for the introduction of the principle of oscillation, or repetitive motion, to timekeeping.

From that point the development of timekeeping went into relative hyper drive. By the mid 20^th century the accuracy of clocks had improved to the incredible. Atomic clocks are now able to keep time to within 1 second per 100 million years.

Along with the evolution of the mechanisms involved in timekeeping the size, shapes and designs of clocks have changed – many, many times. Some of the more interesting designs include carriage clocks that were designed with a handle on top to make it easy to carry the clocks while traveling. The method of travel at that time – carriages! Mantel clocks have been around for hundreds of years and were and are popular for use above fireplaces.

Cuckoo clocks came into being sometime around the turn of the 17^th century. By the middle of the eighteenth century clockmakers from the Black Forest Region of Germany developed an affection for the designs. Handmade Black Forest cuckoo clocks are now world famous, and collected for their distinctive designs and beauty.

The rolling ball clock was patented in the 1970s and has proved to be entertaining to watch as the balls are scooped up and dumped on rails that represent the hours and minutes. Rolling ball clocks have been sold all over the world as toys and novelty items. The world’s largest model, the AION Rolling Ball Clock in Lucerne, Switzerland, is four stories tall.

There are alarm clocks that scream louder than a jackhammer and some that actually shake the bed. There are clocks that project the time on a wall or the ceiling.

The scariest clock is the U.S. Debt Clock that keeps track of the financial condition of the United States. It is actually a compilation of thirty-nine statistical tracking devices that keep track of the country’s financial state.