disc with a serrated edge, used as an astronomical tool, is mentioned in the title of the
Star Gauge. Early sources focused on the circular poem composing the outer border of the grid, consisting of 112 characters. Later sources described the whole grid of 840 characters (not counting the central character , meaning "heart", which lends meaning to the whole but is not part of any of the smaller poems). The text of the poem was circulated continuously in medieval China and was never lost, but during the
Song dynasty it became scarce. The 112-character version was included in early sources. The earliest surviving excerpts of the entire grid version date from a 10th-century text by
Li Fang. While sources agree that Su was a talented poet, the background story and interpretation of the poem changed over the centuries, from the lament of a wife longing for her husband, to a wife worrying about her husband fighting on the frontier, to a jealous wife competing for her husband's affections. By the
Tang period, a popular story of Su Hui's life was attributed to empress
Wu Zetian, though this is likely a creative misattribution for narrative effect. This included the following description of the poem: Dou Tao of Qinzhou was exiled to the desert, away from his wife Lady Su. Upon departure from Su, Dou swore that he would not marry another person. However, as soon as he arrived in the desert region, he married someone. Lady Su composed a circular poem, wove it into a piece of brocade, and sent it to him. Another source, naming the poem as
Xuanji Tu (
Picture of the Turning Sphere), claimed that the grid as a whole was a palindromic poem comprehensible only to Dou (which would explain why none of the Tang sources reprinted it), and that when he read it, he left his desert wife and returned to Su Hui. Some 13th-century copies were attributed to famous women of the Song dynasty, but falsely so. The poem was also mentioned in the novel
Flowers in the Mirror. ==See also==