Introduction to the silk burning furnace: There is a silk burning furnace in the southwest of the corridor of the Confucius Temple in Beijing. The furnace is rectangular in shape, covered with a hilltop roof, and the interior of the furnace is covered with green glazed bricks, making it solemn and eye-catching. The ancients believed that only by burning the offerings, Confucius' spirit in heaven could receive them. Whenever the offerings were burned, green smoke would rise up to nine heavens.