Is the building southeast 15 degrees the same as the geographical feng shui southeast 15 degrees? How to determine?

Similarly, although geomantic omen is based on the compass, the ancients have long known the existence of the earth's magnetic declination. So "meridian" should be the correct direction of the north and south of heaven and earth. Because of the deviation of the south of the Yangtze River, it is difficult to use the meridian, so Bingren participated. "

The meridian needle here is geomagnetic north and south, and the sewing needle between C and N is geographical north and south.

The above words mean that when the geomagnetic north and south are the same as the geographical north and south, the meridian needle is used; Just like Jiangnan, when the geomagnetic north and south are inconsistent with the geographical north and south, the needle is sewn with a needle.