Introduction to the 10,000-person ball: The 10,000-person ball is hung in the "in the middle hall" room and is one of the three treasures of the Qiao Family Courtyard. It is a spherical mirror, and the image can be seen from any angle in the room. When it is brought to the center of the ball, sometimes the number of visitors fills the room, and all the images in the ball are included. It is called the Ten Thousand People Ball and it is well-deserved. This object is a real object from the Qing Dynasty.