Clock Information

A clock is a timekeeping device and a precision instrument for measuring and indicating time. Clocks are usually distinguished by the size of the inner machine. According to international practice, those with a diameter of more than 80 millimeters and a thickness of more than 30 millimeters are called clocks; those with a diameter of 37-50 millimeters and a thickness of 4-6 millimeters are called pocket watches;

those with a diameter of less than 37 millimeters are called wristwatches; and those with a diameter of not more than 20 millimeters or a core area of not more than 314 square millimeters are called women's watches. The watch is one of the smallest, strongest and most precise machines ever invented by man.

Expanded Information;

Many people always think that clocks and watches first originated abroad, in fact, it was Chinese clock and watch technology that was first introduced to Europe, and the Europeans later produced well-crafted clocks and watches. When it comes to Chinese clocks and watches, many people's first reaction may be sundials, water clocks and so on, but these ancient timekeeping tools in the strict sense can not be called clocks and watches, can only be called a timer.

In the Swiss World Watch and Clock Journal, it is written that "the escapement used in modern mechanical clocks and watches originated from the invention of Su Song in ancient China", and Joseph Lee, the famous British historian of science and technology, said that "Su Song combined the clock and watch machinery with astronomical observation instruments, and since then, he has succeeded completely in the principle of the escapement, and he is more successful than Su Song. He was six centuries ahead of Robert Hooke. He was six centuries ahead of Robert Hooke, and seven and a half centuries ahead of Fang and Pei and Hooke, who are both recognized in the West as the inventors of astronomical clocks and watches." In 1099, Su Song, the chancellor of the Northern Song Dynasty, presided over the construction of a water-carrying instrument that resembled a modern clock, with an error of just one second per day.

Source of reference; Baidu Encyclopedia-Clock