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The first volume of Tiangong Wu Kai includes grain planting, cotton and linen, sericulture, reeling, dyes, food processing, salt making, sugar making and so on. Described the production process and experience of agricultural and sideline industries all over the country at that time. The book talks about the method of "ashes dipped in seedling roots", which is the earliest record of rational utilization of phosphate fertilizer in the agricultural history of China. The book also describes for the first time the hybrid of different silkworm moth varieties "produces fine varieties".
The middle volume includes brick making, pottery making, copper making, iron making, shipbuilding, lime mining, coal burning, sulfur, oil pressing, candle making and paper making.
The second volume includes the mining and smelting of hardware, weapons, gunpowder, Zhu Mo, the manufacturing of pigments and sake drugs, and the mining and cutting of pearls and jade. The variety, dosage, source, tool structure and manufacturing technology of raw materials are described in detail and carefully studied in the book. This book covers almost all kinds of industries from life to production.
Baidu Encyclopedia-Tiangong Wu Kai