Lu Ji was a man of Huating, Wu County (today's Songjiang, Shanghai) in the
period of the Three Kingdoms and a scientist.
When he was six years old, he went to Jiujiang with his father to call upon
Yuan Shu. The latter entertained them with oranges and Lu Ji hided two oranges
under his clothes.
When they departed, the oranges fell to the ground and Yuan Shu laughed: "You
came to my home as a guest. Why should you take away the host’s oranges when you
Lu Ji answered: "My mother likes to eat oranges and I want to take them back
for my mother." Yuan Shu was very surprised to learn he was pious to his mother
at such a young age.
When Lu Ji was grown up, he was knowledgeable and knew astronomy and the
calendar. He drew the Armillary Sphere Map, annotated the Book of Changes and
wrote the Annotations on Canon of Supreme