Kao Gong Ji (The Records of Examination of Craftsman)
This is an important work of science and technology among the classics before the Qin Dynasty. Its author is unknown. Scholars have found that this book was an official document of the Qi state of the Spring and Autumn Period. It was used to guide the handicraft industries, including the examination and assessment of craftsmen. The book covers carpenters, metalworkers, leatherworkers, porcelain makers, and many others. It also records the manufacturing of vehicles, weapons and musical instruments, and the building of houses.