Although the political unity and governmental strengh for a technology policy of China was far less than assured during the 3rd to 6th centuries, we can observe a further development of all science fields. Agriculture as the case of feeding the population saw an improvement of crossbreeding, crop selection and many other fields, described in books like Jia Sixie's 賈思勰 Qimin Yaoshu 齊民要術. The first private parks and gardens came up. Machines were constructed for irrigation, food processing and transport. Brewing (niangjiu 釀酒) and the production of sugar from malt (maiya 麥芽) and sugar cane (zhe 蔗) became more refined. Craftsmenship saw its main field of development in the invention of glazed earthenware (youtao 釉陶) and the first porcelain (ciqi 瓷器), with a soft green glazing in the south (qingci 青瓷) and black glazing (heici 黑瓷) mostly in the north. Architecture found new challenges in the construction of Buddhist pagodas (fota 佛塔) and temples (siyuan 寺院), and in the monastery grottoes (shiku 石窟) in the north. Daoist scholars made great efforts to find the elixir of immortaility. Their experiments (liandan 煉丹) contributed to the development of alchemy and chemistry. Likewise, medicine became an integral part of Chinese science: - general description, acupuncture and moxibustion in the book Huangdi Neijing 黃帝内經 - acupuncture and moxibustion in the books Zhenjiu Jiayi Jing 針灸甲乙經 by Huangfu Mi 皇甫謐 - pulse diagnostics in Wang Shuhe's 王叔和 book Maijing 脈經 - general medicine in Long Qingxuan's 龔慶宣 book Liu Juanzi Guiyifang 劉涓子鬼遺方 and in Ge Hong's 葛洪 Zhouhou Beijifang 肘后备急方 - pharmakology in Tao Hongjing's Bencaojing 本草經, Cheng Yanzhi's 陳延之 Xiaopinfang 小品方, and the book Leigong Baozhi Lun 雷公炮炙論 Astronomy and mathematics always played an important role for Chinese scientists. A couple of old mathematical books is combined to the "Ten Classics of Mathematics" (Suanshu Shijing 算書十經), among these Liu Hui's 劉徽 Haidao Suanjing 海島算經 and Zu Chongzhi's 祖衝之 Zhuishu 綴術 (lost). Chinese mathematicians and astrologers of this historical period developed the method of parallax (chongcha 重差) to determine the distance of stars. Calculation with segments of a circle (geyuan 割圓) was known as well as the calculation of the constant Pi π (yuanzhoulü 圓周率).