The scientist Lu Ji came from Huating of Wu County in the State of Wu from the Three Kingdoms Period, the location of which is Songjiang in Shanghai at present. At the age of 6, he accompanied his father Lu Kang to Jiujiang to pay a visit to Yuan Shu, who then received them with oranges in his clothes. Just before their departure, the oranges fell down to the ground.
Yuan Shu mocked at them and asked if it was necessary fro them to hide some oranges when they were invited to be guests just before parting. Lu Ji replied that his mother liked eating oranges very much so that he would bring some back to let his mother have a taste as well. Yuan Shu was surprised to see his filial piety, too young though he was. As an adult, he was erudite, versatile and even proficient in astronomy and calculation. He drew the Chart of Heaven, gave notes to the Book of Changes, and composed the Explanation for Taiyuan Scripture.