Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. Pages: 56. Chapters: Zhang Heng, Wang Mang, Zhang Qian, Zhang Liang, Chao Cuo, Dongfang Shuo, Zhang Tang, Du Shi, Cai Yong, Su Wu, Jin Midi, Ban Zhao, Yuan An, Liu Xin, Dou Wu, Liu Biao, Dong Zhongshu, Ban Gu, Sang Hongyang, Jia Yi, Ning Cheng, Xiahou Ying, Yang Xiong, Shi Xie, Huan Tan, Han Fu, Qiao Xuan, Liu Xiang, Feng Liao, Sima Xiangru, Cui Yuan, Zhu Jun, Di Shan, Ban Biao, Yuan Ang, Zhang Wen, Zhao Qi, Lu Zhi, Liu Yu, Ma Rong, Hua Xin, Huan Jie, Yuan Yi, Sima Fang, Sima Jun, Liu Fu, He Yong, Zhang Anshi, Kong Zhou, Minister over the Masses. Excerpt: Zhang Heng (simplified Chinese: traditional Chinese: pinyin: Zh ng Heng; Wade-Giles: Chang Heng; 78-139 CE) was a Chinese astronomer, mathematician, inventor, geographer, cartographer, artist, poet, statesman, and literary scholar from Nanyang, Henan. He lived during the Eastern Han Dynasty (25-220 CE) of China. He was educated in the capital cities of Luoyang and Chang'an, and began his career as a minor civil servant in Nanyang. Eventually, he became Chief Astronomer, Prefect of the Majors for Official Carriages, and then Palace Attendant at the imperial court. His uncompromising stances on certain historical and calendrical issues led to Zhang being considered a controversial figure, which prevented him from becoming an official court historian. His political rivalry with the palace eunuchs during the reign of Emperor Shun (r. 125-144) led to his decision to retire from the central court to serve as an administrator of Hejian, in Hebei. He returned home to Nanyang for a short time, before being recalled to serve in the capital once more in 138. He died there a year later, in 139. Zhang applied his extensive knowledge of mechanics and gears in several of his inventions. He invented the world's first water-powered armillary sphere, to represent astronomical observation; improved t...