A Short History on Clocks

A question that could have been asked for thousands of years is, “What time is it?” Throughout history many devices have been invented to answer this question. From sundials to atomic clocks, mankind has pursued this quest.

In the earliest recorded times, the position of the sun in the sky gave the best indication of passing time. When the sun was directly overhead, it was midday. During night-time and cloudy times it was impossible to calculate the time of day using this method. People started using the shadow cast by an object in the sun to become more precise and to save their eyesight as they did not have to look up to the sun anymore. Egyptians are credited as being the first to construct larges obelisks to cast a shadow in about 3500BC. By 1500BC, refined sundials were in use. Another invention during these early times was the hourglass using water as the medium. These too had their limitations, particularly in calibration and changing temperatures. Sand was only introduced into the glass hourglasses in about 700AD.

Mechanical clocks were first invented in the 14th century. These timepieces used springs, levers and escapements and generally had no hands or faces, but simply chimed a bell on the hour. A little later the faces and hands appeared.

In the 15th century, coiled springs were developed and the size of clocks reduced significantly. It was also the coil spring that enabled the wrist watch to be later invented.

The clocks till this time were not very accurate, however the invention of the pendulum clock in 1656, by Christiaan Huygens, allowed accuracy to come into play. His pendulum clock was accurate to within one minute each day, rather than the fifteen minute accuracy of the earlier spring driven clocks.

Early in the next century, the British Parliament offered a substantial reward for someone to solve the problem of accurately defining longitude. There were many theories on how this could be done, and the two dominant theories relied on either the stars or an accurate timepiece. John Harrison eventually won the prize after a number of tries with a clock that lost only five seconds on six and a half weeks at sea.

During the 19th century with the industrial revolution in full swing, many advances were made enabling mass production of timepieces. The price of clocks came down significantly and they become common use items amongst the ordinary people. Watches were mainly pocket watches.

It was not until 1884 that most countries agreed to time zones, with clear relations between them. They are still in place today. “Greenwich Mean Time” is still regarded by many as the place where time starts.

Wrist watches were only worn by ladies at first, but during WW1 men started wearing them and it was not long before wristwatches become more common than pocket watches. It has been said that the soldiers found wristwatches much more suitable than pocket watches during that war.

Since the 1960’s most watches are now powered by a “quartz movement” rather than a spring movement. These watches are significantly cheaper and are very accurate. GPS units, fish finders, mobile phones and many other interesting gadgets can now be built into wristwatches. Where will it end?

There will no doubt be further advances in man’s quest to answer the question, “What time is it” more accurately.