Draw clockwise: draw a circle and then a small circle. There is a dot above and below the small circle. This dot looks like a hat. When you take it out, it comes out clockwise.

Minute hand drawing: draw a big circle first, and then draw a small circle. There is a small dot above and below the small circle, like a hat. Take this dot out and the minute hand will be drawn.

Second-hand painting: draw a big circle first, and then a small circle. There are dots on the top and bottom of the small circle, like a hat. Take this dot out and the second hand will be drawn.

What is a clock?

Clock is called clock for short, and all timing devices can be called timing instruments. Clock in modern Chinese generally has two meanings, one is the general name of all kinds of clocks and watches, and the other refers to large clocks and watches, especially clocks and watches with pendulums in mechanical structure.

Clock is one of the earliest objects invented by human beings, because it is necessary to measure the time interval continuously. Some natural time intervals (such as day, leap month and year) can be obtained by observation, and shorter time intervals need to use clocks. For thousands of years, the principle of timing equipment has also changed greatly. A sundial is the change of time by the shadow of an object on a plane. There are many instruments to calculate the time interval, including the most widely known hourglass.

The water clock matched with the sundial may be the earliest timing instrument. Europe invented the escapement in 1300, and later created the first mechanical clock, which can use oscillating timing equipment such as balance wheels.

Clockwork-driven clocks appeared in the15th century, and the watch industry began to develop in the15th century to16th century. 1656 invented the pendulum clock, so the accuracy of timing was further improved. At that time, navigation required the accuracy of time, which also promoted the reliability and accuracy of clocks and watches. The electronic clock was patented in 1840, and the development of electronics in the 20th century produced a clock with no mechanical movement at all.

At present, the timing element in a clock is a harmonic oscillator, an object that oscillates at a fixed precise frequency. The harmonic oscillator can be a simple pendulum, a tuning fork, a crystal or an electron oscillation when an atom emits microwave.

Analog clocks use hands and angles to represent time, while digital clocks use numbers to represent time. There are two kinds of time expressions: twelve-hour system and twenty-four-hour system. Most digital clocks use electronic equipment, liquid crystal, LED and vacuum fluorescent display to display the time. Clock function is also one of the standard functions of computers, mobile phones or tablets.

For convenience, distance, telephone or the needs of the blind, an auditory clock is used to tell the time by sound. In order to meet the needs of the blind, there are also clocks for the blind that can sense their own time by touching, some of which are similar to the traditional time, but by adjusting their design, they can directly touch the surface to know the time without affecting the timing function. Timing technology is also constantly developing.