China's ancient physical knowledge is scattered in the Wu Kai of Tiangong, such as water lifting tools (trucks, beaches, windmills), rudder, pouring steel, clay casting kettle, lost wax casting, methods of removing coal mine gas, brine absorber (pump) in salt wells, melting extraction methods and so on. It is clearly pointed out in the hardware that zinc is a new metal and its smelting method is recorded for the first time.
"Tiangong Wu Kai" records the case of farmers cultivating new varieties of rice and barley, studies the influence of soil, climate and cultivation methods on the variety change of crops, and notes the variation caused by the hybridization of different varieties of silkworm moths, which shows that the variety characteristics of animals and plants can be changed through human efforts, and draws a scientific opinion that "soil veins change with time, and species are divided by soil and water"
Other contents in the book
The book "Heavenly Creations" describes in detail the types of raw materials, places of origin, production technology and equipment of various crops and handicrafts, as well as some production organization experiences. The first volume records the planting and processing methods of grain, beans and hemp, the spinning and dyeing techniques of silk cotton and ramie, and the production process of salt and sugar.
The contents of the book include the production of bricks and ceramics, the construction of vehicles and boats, the casting and forging of metals, the mining and firing of coal, lime, sulfur and alum, and the methods of oil extraction and paper making.