《明史·志·卷六》
四年五月癸亥日，干清宫束丹墀旋风突然刮起，内官监大如屋顶的铁片在空中盘旋，坠落在西墀，铿訇之声如打雷。
四年五月癸亥，乾清宫东丹墀旋风骤作，内官监铁片大如屋顶者，盘旋空中，陨于西墀，铿訇若雷。
On the Guihai day of May, year 4, a cyclone suddenly arose at the eastern Danchi of Qianqing Palace, a piece of iron as large as a roof above the Internal Affairs Office spun in the air and fell on the western Danchi, making a noisy sound like thunder.