Krafts Clock Repair

This is a brief history of clocks for those who are interested. For more in depth knowledge, there are many fine web sites on the internet that have a wealth of information on clocks and their history.

Time and its measurement, or horology, as it is called, is really a measurement of small amounts of time less than the year and month. It divides the day into precise intervals whereby we can govern our daily lives.

The first clocks have been around since before 4000 BC. These were water clocks. Water would pour out of a container and turn a wheel that was connected to a mechanism that showed time. There was only one hand on clocks back then, that was the hour hand.

It wasn't until 1577, when Jost Burgi invented the minute hand.

Christian Huygens invented the pendulum clock from Galileo's discovery that the pendulum swings at a determined rate and could be a very precise instrument for measuring small intervals. the pendulum is not really a swinging object, but is in reality a falling object. Its physics is quite complex, but in short the longer a pendulum is the slower the clock will run, and the shorter the faster. Pendulums are "set" or rated, by a bob that is on the shaft. The bob is the round part on the bottom of the pendulum rod. It does not need to be round but can really be any shape. Its function is to add weight to the pendulum rod. If the bob is raised, it effectively makes the pendulum rod shorter thus speeding up the clock. If it is lowered, the opposite occurs and the clock is slowed. Very accurate time keeping can be achieved by this instrument.

A clock works by allowing a power source to be unwound or let down at a predetermined rate. The power can be either a spring that is wound up or a weight. Weights are the most accurate since the pull of gravity is constant.

The first watch was invented in Germany around 1504 by Peter Henlein. It was not very accurate, but did represent the first watch.

 

Battery clocks followed, then quartz clocks were invented. In 1927 Warren Marrison, noticed that a quartz crystal resonated at a very precise frequency. This effect is now used in all quartz clocks.

The most accurate in clock in the world are the atomic clocks that use a radio active isotope that has an extremely accurate frequency. Its invention came about through research in radar in 1957.

Cesium is used and its frequency, around 9.1 Giga Hertz, is so accurate that time can be measured to within one millionth of a second per year.