We know that the same name magnetic poles repel each other and the unusual magnetic poles attract each other. Then, the earth itself is a huge magnet, its Antarctic and the north pole are located at the end of the earth. According to the rule of interaction between magnetic poles, the Arctic compass and the geomagnetic Antarctic attract each other, the compass Antarctic and the geomagnetic Arctic attract each other. So when the compass is stationary, its north pole always points to the northern end of the earth, and the south pole points to the southern end of the earth.
In the Eleventh Century, Chinese scientists found that the direction of the compass is not the South and the north of the earth, but a slight deviation from it. That is to say, the poles of the earth do not coincide with the poles of the earth's magnetic field. The N pole of geomagnetism is near the geographical Antarctic. The S pole of geomagnetism is near the earth's North Pole. When Columbo, a navigator in Italy, crossed the the Atlantic (1492), it was observed that this phenomenon is more than 400 years later than that of Chinese scientists.