Clocks: Multi-Functional Time-Keepers

The first time-keeping tools came about around 6,000 years ago in the Middle East and northern Africa. Cultures with an interest in tracking time were heavily involved in strict, religious rituals.

Useful, Accurate Time-Keeping Early time-keeping devices were lamps or candles with markings along the sides divided into equal portions. For any timing device to be accurate, it must offer a system of time portions divided identically and reliably. In order to be useful, the device must provide a way to display this ongoing process. The described lamps and candles, as well as ancient instruments that marked the daily progression of the sun's movement across the sky, were both useful and accurate, according to existing technology. The Egyptians An obelisk is a lofty, thin tower used by the Egyptians in 3500 B.C. to track time. The obelisk formed a shadow cast by the sun's movements across the sky. Dividing the day in half, at noontime the shadow was its longest - and it reached its ultimate length at noontime on the longest day of the year. Likewise, the obelisk's shadow was its least length on the shortest day of the year.

Using Sundials and Merkhets
The first instrument to divide daylight into 12 hours came about around 1500 B.C. The Egyptian sundial was used during the day, while a merkhet, an astronomical tool used to track star patterns, helped the Egyptians keep time at night. By 30 B.C., there were some 13 types of varying, intricate sundials in existence.

The Greeks
The Greeks used containers called clepsydras to keep track of time. Developed around 325 B.C., stone clepsydras had markings along their curved sides and a hole that caused the water in the container to drip at a constant rate. Time could be tracked according to the water level in relation to the clepsydras' markings. One advantage that the clepsydras had over obelisks or sundials was the ability to use them during the night, as well as the day. Evolutions in development eventually brought about moving pointers and jingling bells at certain times of the day, much like today's alarm clocks.

The Dutch, Pendulums and Beyond
A Dutch scientist, Christian Huygens, invented the pendulum clock in 1656. This was an improvement on the weight-operated clocks that had become the norm in Italy during the 1300s, verge-and-foliot. Huygens worked tirelessly to bring his remarkable invention to the point where it tracked and displayed time to within 10-second-error precision. Clocks continued to evolve in accuracy and reliability, eventually becoming the quartz crystal clocks of the 1900s - inexpensive precision available to the masses. Today, the abilities of atomic clocks are astounding in their technology.

Variety of Modern Clocks
Today, clocks of all varieties can be found just about everywhere. Wristwatches, in addition to being convenient, can also be status symbols. Mantle clocks are charming and functional. Digital clocks are precise to within a fraction of a second, and are used to judge the winner at many a finish line. Grandfather clocks are precious heirlooms, cherished by generations. Finally, the simple wall clock and oven timer keeps you from burning your dinner. Basic clocks today are powered by solar energy, winding mechanisms, or batteries.

Thanks to technological advancement throughout the ages, we consider the ancient art and science of timekeeping not only convenient, but an indispensable necessity.