2. In the era of feudal hierarchy, there was no "drum" in front of the door of a celebrity with no achievements. If you want to decorate the front of the scroll to show wealth, you can also erect a door pillow as high as a stone drum, but only the decorative part next to the door should be square, which is different from the "drum" and is still called "pier" no matter how high it is. Therefore, in feudal society, drums were placed at the entrance of yamen, while dignitaries had the right to place stone drums at the door. The design on the stone drum has many identities. Ordinary people can only put pillows at the door, so the stone drum represents the meaning of being rich or expensive.