"Laojun Brick" is a brick erected at the top of the fire path to see the fire degree when burning bricks in brick kiln. In the kiln, bricks and tiles are packaged in the form of "a horse riding a lantern" and "crossing a bridge with two legs". After sealing, a green brick can burn an average of one and a half kilos of firewood or one kilo of coal. Before ignition, you should respect your grandfather and old gentleman. Generally, you should burn it with normal fire (about 500℃) for 15-20 days, and then burn it with big fire (above 1000℃) for two days and two nights. When you see the "Laojun brick" (that is, the standard brick in the kiln) turn into persimmon yellow, you will start baking bricks. Bricks and tiles turn blue and cool before they leave the kiln.
Later, it was used by people to ward off evil spirits. Cinnabar wrote "Taishan stone dares to block" and used it as a town object.