Types Of Clocks
A clock is an instrument used to measure time. The concept of such a device which measures the time intervals is not new and clock is perhaps one of the oldest inventions of man. However the type of time measuring clocks used by the ancient civilizations worked on different principles and included water clocks, sand glasses and sun dials.
The Chinese were the first to develop an astronomical clock in the 11th century but the first ever proper public clock was developed in Europe in 1353 A.D. Eventually with the advent of modern sciences, accurate and precise clocks were invented and now today the man has created clocks which measure time accurate to the millionth of a second.
The major types of clocks are:
- Mechanical clocks
- Electrical clocks
- Quartz clocks
- Atomic clocks
The mechanical clocks are the clocks which are powered by either coiled springs or falling weights. In other words, any clock which is not powered by electricity is a mechanical clock.
There are two types of mechanical clocks:
- Spring Clocks
The spring clocks were the first one to become the public clocks in the 1300s. The clocks invented back then were large and used to be in churches or on top of large buildings. They chimed a bell at given intervals of times. They were powered by simple springs.
Spring Mechanical clocks progressed with time in their accuracy and structure. In 1490 when the coiled spring was invented, it took place of the simple spring in cocks which resulted in more accurate and smaller clocks. With the use of coiled springs clocks started to appear in houses of every individual. Mantel clocks and desktop clocks were also invented as result. The mechanical clocks produce the typical 'tick tock' sound of the clocks
- Pendulum Clocks
The difference between the above mentioned mechanical clock and this mechanical clock is that this clock is powered by a pendulum.
A pendulum clock was first invented by Christian Huygens in 1656 based on a model developed by Galileo. The pendulum clocks immediately took place of the spring mechanical clocks at that time as they were accurate to a minute in a day as compared to the coiled spring mechanical clocks which were accurate to fifteen minutes per day. Pendulum clocks also evolved with the passage of time.
In 1721 George Graham invented a pendulum clock accurate to a second.In 1921 W.H short produced a double pendulum clock which proved to be the most accurate pendulum clock.
The electrical clocks are the clocks which run on electricity provided by either batteries or mains power. The first electric clock was developed in 1840 by Alexander Bain. But then the mechanical clocks were mostly in use and not much attention was paid to the electric clocks.
Electrical clocks progressed slowly after that. In 1918 H.E Warren produced the first clock with the battery. As the twentieth century proceeded electrical clocks overcame the mechanical clocks and now they are the major form of clocks used all over the world. Common electrical clocks are: quartz clocks and master clocks.
Although quartz clocks are a type of electrical clock but they are mentioned separately because at the moment they are the most commonly used clocks in the world. In fact they have been in power since the early part of the twentieth century.
A quartz clock consists of a quartz crystal which is made to vibrate by electricity provided via batteries. The quartz clocks are very accurate and every oscillations of the crystal in the circuit with in the clock counts to a time interval of a second.
The first quartz clock was invented in 1927 by W.A Morrison. Since then many developments and improvements have been made to these clocks to improve their accuracy.
Atomic clocks are highly accurate clocks which use the frequency of absorption and emission, of the electromagnetic radiation, of a compound to divide the intervals of time.
Atomic clocks were first invented in 1955 by Dr. L Esson who made the use of caesium for measuring time intervals. Later more atomic clocks have also been built based on hydrogen and rubidium.
Although atomic clocks are highly accurate and are long lasting, they are very expensive because of which they are used only in laboratories.