When did the accurate mechanical clocks appear?

When did the accurate mechanical clocks appear?

The clock was invented part by part. In 1577, Jost Burgi invented the minute hand. Burgi’s invention was part of a clock made for Tycho Brahe, an astronomer who needed an accurate clock for his star-gazing.

In 1656, Christian Huygens, a Dutch scientist made the first pendulum clock regulated by a mechanism with a ‘natural’ period of oscillation. Although Galileo Galilee, sometimes credited with inventing the pendulum, studied its motion as early as 1582, Galileo’s design for a clock was not built before his death. Huygens’s pendulum clock had an error of less than 1 minute a day, the first time such accuracy had been achieved. His later refinements reduced the error to less than 10 seconds a day. In 1721, George Graham improved the pendulum clock’s accuracy to 1 second a day by compensating for changes in the pendulum’s length due to heat variations. John Harrison, a carpenter and self-taught clock-maker, refined Graham’s temperature sation techniques and added new methods of reducing friction. By 1761, he had built a marine chronometer with a spring and balance wheel. It 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 10 times better than required. One of the most famous, the W.H Shortt clock, was demonstrated in 1921. The Shortt clock almost immediately replaced Riefler’s clock as a supreme timekeeper in many observatories. This clock consists of two pendulums, one a slave and the other a master. The slave pendulum gives the master pendulum the gentle pushes needed to maintain its motion, and also drives the clock’s hands. This allows the master pendulum to remain free from mechanical tasks that would disturb its regularity.