Compass, also called Sina, is mainly composed of magnetic needles installed on the shaft. Under the action of natural geomagnetic field, the magnetic needle can rotate freely and keep in the tangent direction of magnetic meridian, and the north pole of the magnetic needle points to the geographical north pole, so the direction can be distinguished by this property. It is often used in navigation, geodesy, tourism and military affairs. The invention of the compass with physical direction indication consists of three parts, namely Sina, compass and magnetic needle, all of which belong to the invention of China.
Geomantic compass, also known as compass, compass, Luo Geng, compass, etc. It consists of Tianchi, Tianxin Ten Classics and Inner Plate. The whole disk can rotate back and forth, which is a measuring tool used by Mr. Feng Shui in Feng Shui. In addition, it also has the function of blocking bad luck. For families with bad luck in the house, it can be placed in the middle of the house or in the living room near the wall in the north-south direction, which can improve feng shui and enhance good luck.