Two thousand scholars worked on the work, incorporating eight thousand works from ancient times up to the early Ming Dynasty. They covered an array of subjects, including agriculture, art, astronomy, drama, geology, history, literature, medicine, natural sciences, religion, and, technology, as well as descriptions of unusual natural events. The Encyclopedia, which was completed in 1408, comprised over 11,000 manuscript volumes occupying 40 cubic metres (1400 cubic feet).
Because of the vastness of the work, it could not be block-printed, and it is thought that only one other manuscript copy was made. In 1557 under the supervision of the emperor Jiajing (嘉靖) the Encyclopaedia was narrowly saved from being destroyed by a fire which burnt down three palaces in the Forbidden City. Afterwards, Jiajing ordered the transcription of another copy of the Encyclopedia.
The original copy has disappeared from the historical record. The second copy was gradually dissipated and lost from the late-18th century onwards, until the roughly 800 volumes that remained were burnt (in a fire started by imperial Chinese forces) or looted/rescued by European and American forces during the Boxer Rebellion in 1900. Only around 400 volumes remain, in libraries and private collections around the world.
What happened to the original is not known. There are four hypotheses: