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Did you know… |
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Timekeeping is as old as civilisation itself and the clocks offered on this website reflect over 5000 years of evolution.
In ancient civilisations the working day was largely controlled by daylight and therefore it is not surprising that the earliest system of dividing days into parts were the sun clocks developed by the Egyptians around 3500BC. Obelisks, and later the more accurate sun dials, cast a shadow indicating the rotation of the earth in relation to the sun and the solar system. These instruments clearly indicated the two halves of the day and the years longest and shortest days by the position and length of the shadows. From these measurements the Egyptians developed a calendar that had twelve thirty day months, that is a 360 day year.
To mark the passing of time at night the Egyptians created an instrument called a merkhet. By aligning this instrument with the pole star the passage of time was indicated as the stars crossed the meridian.
The first instruments created that did not rely of the rotation of the earth to indicate the passing of time were called clepsydra, these were water clocks that appeared in Greece in around 350BC. Although lacking in accuracy, the regulated flow of water into or from a calibrated vessel indicated the time during the day and at night. A similar device was the hourglass that allowed sand to flow at a constant rate between two glass bulbs. At about this time, calibrated candles and oil lamps were also used to indicate the time of day.
The number system that we use to this day for telling the time is thought to be based on the Babylonian system that had a base number of 60. A system that divides an hour into 60 minutes and each minute into 60 seconds, and then reverts to the decimal system for fractions of a second can be confusing. Perhaps this is the reason that young children have difficulty with telling the time from a traditional clock! It was the Romans who divided the day into two halves at midday, that is the anti-meridien (am) and the post-meridien (pm).
In the 14th century springs and weights were used to provide power for the first mechanical clocks. From this time onwards the accuracy of clocks improved as superior devices were developed to allow these sources of energy to escape at a constant rate through gears and levers that recorded the passage of time. Typically the first mechanical clocks were built for public places.
The principle of using the consistent rate of oscillation of the swing of a pendulum to regulate a clock was described by Galileo in the 16th century. However, the first such timepiece was made in the Hague by Soloman Coster in 1656 to a design by Christian Huygens the Dutch Physicist. The principle was quickly adapted in the United Kingdom by Ahaseurus Fromanteel in 1658. These clocks achieved an error of less than a minute a day.
At about the same time Robert Hooke, secretary to the Royal Society and an associate of Isaac Newton, developed the balance wheel and spring assembly, the principle that allows the power of a timepiece to escape at a constant rate that is still used today in small mechanical clocks and watches.
Accuracy was further improved by the development in England of the “Anchor” escapement by William Clement in 1671, and the temperature compensation features such the compensated pendulum created by George Graham in 1721. John Harrison applied and refined these principles further to create the first Sea Clock in 1761 that achieved an accuracy of plus or minus a second per week. This was an extraordinary achievement that allowed naval navigators such as Captain Cook to accurately establish their longitude position on the high seas for the first time.
The basic principles of these clocks remain unchanged to this day although improvements in design and construction lead to mechanisms that struck a bell to indicate the time on the hour. This was further developed so that clocks could play melodic chimes such as Westminster, St. Michael and Whittington to mark the quarters of the hour. It also became popular for clocks to feature moon dials that indicate the phases of the moon during the lunar month of 29.5 days, or to feature automata such as rocking ships to mark the passage of time.
The significance of the development of mechanical clocks as a prelude to the industrial age was described by John Russell, the Victorian philosopher: “The clock is not merely the means of keeping the hours, but of synchronising the actions of men……….the clock, not the steam engine, is the key machine of the industrial age.”
The next breakthrough in accuracy was achieved in the 1930s by passing an electric current through a quartz crystal causing it to vibrate generating a constant electric signal that can be used to control an electronic clock display. However, the accuracy of these timekeepers has now been surpassed by atomic clocks. The discovery that that atoms and molecules absorb and emit magnetic radiation at a very stable rate over time and space has lead to the creation of cesium atomic clocks that are accurate to one millionth of a second a year!
The aspiration of early clockmakers was to create timekeepers which made it possible to better order and manage our lives and the first clocks made were generally used in public places. The development of mechanical clocks made it possible to have clocks for domestic use. The importance and value of these instruments is reflected in the superb craftsmanship employed in their decoration in the styles of each period of their evolution. Today fine clocks are valued for their functionality and as works of art that have a unique place in every home.
The passing of time has a special significance for each of us and perhaps this is the reason that a gift of a fine timepiece is a perfect way to celebrate a special occasion such as a birthday, anniversary or a milestone of achievement. |
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