Development of clocks
Before 1300 AD, people mainly used astronomical phenomena and continuous movement of flowing materials to time. The clepsydra and hourglass keep time by using the flow of water and sand
Eastern Han Dynasty Zhang Heng manufacturing water leakage to the armillary sphere with gear system and timing cledra connected cledra dripping water to promote the armillary sphere evenly rotating day just improved zhou early mechanical clock northern Song yuan Hu three years (1088) Su Song and Han Gonglian and other creation of water transport instrument image table has used the escape mechanism
In 1350, Italy dandi produced the first simple mechanical clock clock daily difference of 15 ~ 30 minutes, indicating only the hour hand; In 1500 ~ 1510, Henlaith in Germany first used steel spring instead of hammer to create a small mechanical clock with coronal wheel escapement; Galileo galilei in Italy invented the gravity pendulum before 1582; In 1657, Huygens in the Netherlands introduced the gravity pendulum into the mechanical clock to create the pendulum clock
In 1660, Hooker invented gossamer and replaced the corona-wheel escapement with a backward escapement. In 1673 huygens balance wheel and gossamer governor application on the carrying clock; In 1675, Clement made a simple anchor escapement with a fork tile device in England
In 1695 The British Tom Ping invented the I-wheel escapement; In 1715, Graham invented the stationary escapement to compensate for the retreat escapement, which laid the foundation for the development of precise mechanical clocks and watches; In 1765, March invented the free anchor escapement, the predecessor of the modern fork-tile escapement. In 1728 ~ 1759, Harrison of England produced a high precision standard Marine clock; 1775 ~ 1780 British Arnold created a precision table escapement
18 ~ 19 century clock manufacturing has gradually realize industrialized production and has reached quite high level along with the rapid development of electronic industry in the 20th century battery-powered clock, ac electric clock, electric mechanical watch, quartz pointer type electronic watches and clocks, digital quartz electronic clock that another clock, clock difference is less than 0.5 seconds into the combination of microelectronics technology and precision machinery quartzification during the new period
