Introduction to the use of compass
1. Keep the compass level, close to or parallel to the edge of the measured object.
2. Slide the turntable so that the hairpin head of the magnetic needle coincides with two points on the red line of the compass base.
3. To locate the reading direction of the layer pressed by the transparent line.
Before using a compass or compass, the following points need special attention:
1. Pay attention to the fact that there are no ironware, mobile phones, telephone poles, electric boxes, electric towers and other items on your body and near the measurement site. If there is, take it off and avoid it.
2. The disk surface of compass or compass (north) needle must be horizontal, and the pointer cannot rise or fall at the same time. At the same time, we should also pay attention to whether the connection between the compass and the disk is tight, and there should be no looseness or damage.
3. Check whether the compass or compass needle is normal, and don't use it if it is bent.
The evolution of compass:
Before the invention of the compass, the ancients mainly observed the stars to tell the direction. Later, our ancestors invented the south compass and sunlight to distinguish the orientation of the ground plane. In fact, the heliograph is the earliest compass, which divides the ground plane into 12 equal parts, and uses the twelve earthly branches, ugly, cloudy, hairy, Chen, already, noon, health, Shen, Cheng and the sea to indicate the orientation.
The ruins produced in the Han Dynasty are square. Although there is no magnetic needle, it is impossible to measure the direction of the main hall, but 24 directions have been carved, standing layer by layer, which has a direct impact on the Feng Shui compass.
In the Song Dynasty, the site changed from square to round, and the orientation followed the 24-bit system of the site. With the development of the processing industry, the magnetic needle of the compass has changed from the original spoon to the needle, and from the floating magnetic needle to the thimble, which makes the measurement accuracy of the compass change qualitatively, the orientation representation becomes more and more fine, and the compass presents a rough scale. It can be said that the real compass has been produced.