The western han dynasty and the secretary of the state of zhu buy the minister zhu bought the minister to make the woodcutter, while working while reading, afraid of people ridicule, the book is hidden in the mountains, do not take home, this is the name of the place "books" the history. Zhu bought Chen to study hard, even on the way of the log, while walking, studying, this is what is known as "the log book".
Later, "bear wood reading" with shi biao "ox horn hanging book", kuang heng "authentic wall steal light", CheYin hotaru night "sac" story, was seen as China's ancient MingXian study diligently together the most representative example.