Development of Mechanical Clocks and ...!
The concept of the pendulum-clock is credited to Galileo Galilei an Italian physicist, mathematician, astronomer, and philosopher who studied the motion of the pendulum as early as 1582; although he never actually built one in his lifetime.
Acknowledgment for the invention of the pendulum clock is given to Christiaan Huygens, a Dutch scientist, in 1656. Huygens' early clock had an accuracy error of one minute a day - the best achieved at that time. He later improve on this, reducing the clock's error to less than ten seconds a day. Huygens also developed the balance wheel and spring assembly around 1675, which is still found in some of today's wristwatches. This advance improved the accuracy of portable 17th century watches, although it has to be said, only to an error of ten minutes a day.
In London in 1671, a substantial improvement in the form of a new "anchor" or "recoil" escapement, which reduced interference with the motion of the pendulum, was being used in clock building by William Clement.
George Graham enhanced the pendulum clock's accuracy to 1 second per day in 1721, by developing a technique to compensate for changes in the length of the pendulum due to temperature variations on the metals used. This was refined and developed by John Harrison, a carpenter and self-taught clock-maker, who also introduced new methods for reducing friction.
Harrison took up the British government's challenge to develop a means of determining longitude to within one-half degree. By 1761, after a voyage to the West Indies, he built a marine chronometer with a spring and balance wheel escapement that kept time on board a rolling ship to about one-fifth of a second a day, nearly as well as a pendulum clock could do on land, and ten times better than required to win the government’s prize, which was around £6 million in today's currency.
Over the next century accuracy of a hundredth of a second a day became the standard, and refinements led to Siegmund Riefler, in 1889, develop a clock with a nearly free pendulum. The next development of several free-pendulum clocks, was inspired by R.J. Rudd who introduced a true free-pendulum principle around 1898. Of these clocks, the most famous is the W.H. Shortt clock, which was demonstrated in 1921.
This clock almost immediately replaced Riefler's clock as a supreme timekeeper in many observatories. The clock housed two pendulums, the master and a slave. By introducing a second slave pendulum, which gave the master pendulum gentle pushes to maintain its motion, as well as drive the clock's hands. The master pendulum was free from mechanical tasks that would disturb its regularity.
The future of pendulun clocks - Design or Function?
Shortt clock was replaced as quartz crystal oscillators and clocks, developed throughout the 20th century. Now at the begining of the 21st century, computer technology is displacing crystal technology, as time displays become an integral part of the full range of modern computer and media devices; changing the way people relate to and use timepieces.