Zhang Heng

Zhang Heng (Chinese :  t   , s   , p   Zhang Héng ; AD 78–139), formerly romanized as Chang Hêng, was a Chinese polymath from Nanyang who lived during the Han dynasty. Educated in the capital cities of Luoyang and Chang'an, he achieved success as an astronomer, mathematician, inventor, geographer, cartographer, artist, poet, statesman, and literary scholar.