There are many kinds of geomantic compass, such as ternary disk, triad disk, ternary triad dual-purpose disk, easy disk, mysterious disk and unique disk used by various factions. No matter which school's geomantic compass, there must be a layer of twenty-four mountains in the middle. From the north, they are Renzigui, Ugly Genyin, Jiamaoyi, Chen Xunsi, Bingwuding, Shen, Geng Youxin and Xu Ganhai. In order, there are twenty-four directions.
The center of the compass is the directional compass, and the outside is a movable turntable with copper surface and gold characters on the black background, which is called the inner disk or disk. There are circles on the disk, one of which is in 24 directions, and the outermost is a square disk, which is called an outer disk or a square disk. There are four holes in the outer disk, and two fishing lines or glue lines respectively pass through the holes in the middle of the four sides to determine the sitting posture.
When using the compass, hold the outer disk with both hands left and right, and separate your feet slightly. Put the compass between the chest and abdomen, keep it horizontal, not high left and low right, and not high front and low back. Then sit with your back to you and start to stand up straight. The crosshairs on the compass should coincide with the front, back, left and right positions of the house. If the crosshair is not upright, the measured sitting posture will be biased and need to be corrected. After fixing the position of the crosshairs, move the inner disk with both thumbs. When the inner disk rotates, Tianchi will rotate with it until the magnetic needle stops and coincides with the red line in Tianchi.
One thing is very important. One end of the magnetic needle with a small hole must coincide with the two little red dot on the red line, and the positions cannot be misplaced. At this time, it shows that the fishing line (horizontal one) sitting on the right side intersects with all layers of the inner disk, and all kinds of data to be found are displayed in the area covered by this fishing line. There are ten or twenty layers on the compass. Which floor is the direction of sitting? That's the floor of the Twenty-four Mountains, near Tianchi, the "mountain" in the direction of the fishing line and the "mountain" on the side of the fishing line. We use it to indicate sitting. For example, children go to the mountains and sit on the mountains at noon, so they are called sitting in the afternoon. Knowing that you are sitting backwards in the house, put the compass in the center of the whole house, and you can find the direction of the whole house (or palace) from the sitting direction.