This is the only known example of a celebrated type of mirror called “Heart of the Yangzi River”, which was previously only recorded in texts. It was supposedly cast aboard a boat moored in the middle of the Yangzi River. The Eight Trigrams on the mirror are associated with yin and yang. The four mythical creatures (Azure Dragon青龙 of the East, Vermillion Bird 朱雀 of the South, White Tiger 白虎 of the West, and Black Turtle 玄武 of the North) signify the cardinal directions. The inscription states that it was cast on 3 January 759, almost a century before the ship sailed.The full inscription reads, "唐乾元元年戊戌十一月廿九日於扬州扬子江心百炼造成" and can be translated as "Made on the 29th day of the 11th month of the 1st year of the Qianyuan reign of the Tang, in Yangzhou in the midst of Yangzi River, smelted one hundred times".
