Compass plays a very important role in geomantic omen, which is indispensable for surveying the future of Long Mai and determining the direction of geomantic omen bureau. But now, after nearly two thousand years of evolution and improvement of various schools, the compass has formed an extremely complex system, with more and more levels, richer meanings of geomantic omen and more and more categories, which has caused certain difficulties in the selection of compasses in modern geomantic omen.
Geomantic compass can be roughly divided into three types: ternary disk, triple disk and comprehensive disk.
The ternary disk, also known as "Pan Jiang", is mainly characterized by sixty-four hexagrams, which are congenital and acquired. This kind of compass is mostly used by the principles in geomantic omen.
Three-in-one disk, also known as "Yang Gong Pan", is characterized by three layers and twenty-four mountain directions. This kind of compass is mostly used by the situation school in Feng Shui.
Comprehensive plate is a kind of composite plate which combines qi theory and situation. In modern geomantic omen, the theory of qi and the theory of situation are mostly combined, so the comprehensive disk is often used.
Compass has many sizes (disc diameter), but in theory, its upper limit is one foot two inches and its lower limit is two inches eight minutes. In practical use, you should try to choose a larger compass, because the bigger the compass, the more accurate it is, and the requirements for each other in Feng Shui are extremely strict. The so-called "one line is born, one line is dead" and "one line is good or bad" refers to this change. Therefore, the more accurate the compass is, the less likely it is to make mistakes in the process of conditioning Feng Shui.
The compass itself is a very precise tool, so when choosing a compass, we must pay attention to several points: First, the compass pointer must be straight, and it must not be used if it is skewed up and down, not only because these situations will cause visual errors, but also because these situations themselves indicate that there is something wrong with the magnetic field of the compass, so it is natural that correct conclusions cannot be obtained in use.
Second, the red line at the bottom of Tianchi must point directly to the north and south. When the magnetic needle is aimed at the red and black line, the south side should be opposite to the center of the heavenly stem "noon" and the back side should be opposite to the center of the heavenly stem "child", and there can be no difference.
Thirdly, the compass is made of wood, but it must be dry, otherwise there will be deformation of the outer disk, which is usually very small and difficult to observe with the naked eye, but it is enough to affect the feng shui survey. Try not to use metal compasses, especially steel compasses, which are easy to magnetize and will inevitably cause problems after long-term use.
Fourth, the compass needle must rotate flexibly and unimpeded. If the magnetic needle does not rotate smoothly, it means that the magnetic field of the compass is disturbed and inaccurate.
These are just some suggestions for beginners of Feng Shui to choose compasses. In geomantic omen, the choice of compass itself is a science, which requires a lot of experience to use it accurately and understand the subtlety of compass.