zhang heng zhang heng (张衡) (78ad—139ad) was an astronomer, mathematician, artist and literary scholar（文学学者）in the eastern han dynasty of china. born in today’s nangyang county, henan, he was a good writer at age 12. at the age of 16, he left home to pursue(从事) his studying the capital city. he spent at least 10 years of his youth in literary studies and writing. he
