Throughout history, time has always intrigued mankind. From the days of judging the sun position, to today's most accurate timepiece, the atomic clock, time has, without exception, been one of life's constants.
By watching the length of shadows cast by the sun, man realized that the shadow was a more accurate way to tell time, rather than judging the position of the sun. Not long after this observation, the sundial was invented, which was used well into the eighteenth century.
However, man was still not satisfied with the accuracy of time that a sundial provided. Furthermore, not knowing the time during less than sunny conditions or at night, or depending on the Earth's rotation confirmed that another timepiece was necessary.
During the reign of the sundial, two other timepieces were invented; the clepsydra and the sandglass. The clepsydra, also known as a water clock, kept time by the flow of water providing the energy to drive the mechanism. Unfortunately, due to the temperature fluctuations of water, this design was rendered as an unreliable source to tell time.
The creation of the sandglass was more successful. Sand was not dependent upon the position of the sun (or lack there of) or temperature, but only gravity which is constant. Prior to the 15th century, sandglasses were used extensively on naval vessels and even during The Inquisition to limit the torture sessions. Progress demonstrated that sandglasses would be used during speeches, sermons, civic functions and cooking. But these mechanisms still did not satisfy man's obsession in producing a more precise timepiece.
While the Europeans have created most of the timepieces up to this point, China was already working with a new mechanism called an escapement, which was used for their astronomical clocks in doing research and experiments. An escapement is a type of transformer which converts power generated via springs, water or weights, into a constant mechanical motion. Especially important in timepieces that depend on springs and weights to operate, the escapement regulates the uncoiling of the spring, or the drop rate of the weights.
Then in 1657, Christian Huygen, a Dutch scientist patented the first working model of a clock with a pendulum. His design was derived from an observation made by Galileo Galilei, and proved that a pendulum could make the current timepieces more accurate than ever before. Soon, clocks with pendulums were used all over Europe and China, eventually leading to the creation of the wooden case and dial for the timepieces.
Around the mid 1660's, the tall case clock, also referred to as the grandfather clock, made its appearance. These cases concealed the weights and pendulum, allowing for cleaner appearance. As clocks with a case became more popular, man wanted to incorporate the looks of the case with furniture pieces of that era. While cases became more elaborate and their size continued to grow to over ten feet in height, advances were also made to the dial and movement.
Both dials and movement were being manufactured of brass, rather than wood, and including lots of intricate details. In the 18th century, dials received a face-lift with the creation of the break arch and moon dial. The break arch was a scalloped shape added to the top of the current manufactured square dial, allowing one to add detail to even a phase such as "Tempus Fugit" (latin term for time flies). Shortly thereafter, the moon dial was popularized in as much as it could indicate the 29 1/2-day lunar cycle.
In the 19th century, movement became the focus for further improvements. Clock towers used bells to chime a different melody every day of the week. However, until they received chimes, movements made for smaller clocks could only strike the hour. During this century, the tubular and rod chimes, mounted in today's timepieces, became mass marketed, and in turn made famous these three melodies: the Westminster, the St. Michael and the Whittington chimes.
During the 20th century, man still continues to search for more accurate timepieces, consequently the inventions of the quartz movement, the digital movement, and the atomic clock. While crystal and the digital clock rely on numerical calculations, their precision cannot match that of the atomic clock. The atomic clock keeps time via the emanating frequencies of an atom and will lose approximately one second every 1000 years. Even though these timepieces are more precise due to newer technology, they still rely on the basis of a mechanical movement, which functions via power being applied to the mechanism. Although we cannot predict the future, a constant remains: man's continued search for a better and more accurate timepiece.