What is three needles and three reels?

What is three needles and three reels?

The three needles and three discs in the compass refer to the positive needles on the ground, the stitches on the sky disc, and the needles on the human disc.

The ground needle, which is the twenty-four mountain direction, is used to identify the direction and position the vertical direction. The twenty-four mountains are represented by twelve earthly branches and eight stems in four dimensions. The twelve earthly branches are Zi, Chou, Yin, Mao, Chen, Si, Wu, Wei, Shen, You, Xu, Hai, the eight stems are A, B, C, D, G, Xin, Ren, Gui, and the four dimensions are stem , Kun, Gen, and Xun, add up to a total of twenty-four mountains. Use the Houtian Eight Diagrams to contrast with this. There are eight hexagrams around, each with 45 degrees, one hexagram governs three mountains, and each mountain occupies 15 degrees.

The stitches on the daypan are also in twenty-four mountain directions, but the scale is seven and a half degrees worse than the positive needle on the site, which is exactly half a grid. The needle in the human plate is still twenty-four hills, but the scale is fifteen degrees different from the positive needle on the ground, which is exactly one grid.

Although the three needles and three discs are all twenty-four mountain directions, the usage is different.