How to tell the direction with a watch hand?

1, "the hours are half of the sun,'12' refers to the north". Here, "hour" refers to the 24-hour clock, and "half to the sun" refers to the 24-hour clock aiming at the sun after half.

2. For example, at 1 1 in the morning, aim at the sun at 5: 30. If it is at 2: 30 pm (that is, 14: 30), you should aim at the sun at 7: 00, and the direction of "12" is the north.

3. In order to improve the accuracy of judgment, a small town can be erected at the position of "half an hour" (other items with the same effect can also be used), and its shadow can pass through the center of the dial.

Extended data:

A watch refers to a tool worn on your wrist to time/display time. Watches are usually made of leather, rubber, nylon cloth, stainless steel and other materials, and the "meter" showing time is tied on the wrist.

The manufacture and production of watches are based on a simple and witty invention, that is, "clockwork", which can tighten and store energy, slowly release energy to push the running devices and hands in the watch, and achieve the function of displaying time. This spring device in the watch is called the main spring.

The working principle of watches

(Main power). Watch structure A watch consists of a meter head and a strap (clasp). Among them, the parts of the rice head include: movement, case, bottom cover, mirror, characters (often called dial), hands, handles (also called push) and order (required by some tables).

The working principle of watches, watches are precision instruments used to display time. The principle of this instrument is to use a vibration system with constant period and continuous vibration as the standard. If we know the time (vibration period) required for a vibration system to complete a complete watch vibration and calculate the vibration times, then the time after so many vibrations is equal to the vibration period multiplied by the vibration times. That is, time = vibration period × vibration times.

The mechanical watch with balance shaft hairspring adopts balance spring as vibration system. The balance wheel 1 is fixed on the balance shaft 2, and the upper and lower journals of the balance shaft are sleeved in the bearing and can rotate around the bearing. One end of the hairspring part 3 is fixed on the swing shaft, and the other end is fixed on the splint. Due to the elastic deformation of the hairspring, the motion of the balance wheel changes from rotation to reciprocating motion. The balance hairspring system is affected by bearing friction, air resistance and internal friction of hairspring, and the swing amplitude (amplitude) will gradually decay until it stops.

In order to make it vibrate continuously without attenuation, it is necessary to replenish energy to the hairspring system regularly, that is to say, there must be an energy device in the watch. The periodic energy supplement of vibration system is realized by a special mechanism & escapement mechanism. The escapement mechanism is also used to calculate the vibration time of the hairspring system. Therefore, the hairspring system and escapement mechanism are the key devices of mechanical watches.

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