Zhang Heng (78 - 139 AD) was an astronomer, mathematician, inventor, geographer, artist, poet, statesman, and literary scholar of the Eastern Han Dynasty in ancient China. He had extensive knowledge of mechanics and gears, applying this knowledge to several of his known inventions. According to historian Joseph Needham, Zhang Heng was noted in his day for being able to "make three wheels rotate as if they were one" ("neng ling san lun du zhuan ye")". Wikipedia
The definitive Wikipedia entry for Zhang Heng. Wikipedia is the biggest multilingual free-content encyclopedia on the Internet. en.wikipedia.org/wiki/Zhang_Heng
Zhang Heng (78-139), a native of Nanyang in central China's Henan Province , was a mathematician, astronomer and geographer of the Eastern Han Dynasty (25-220). www.chinaculture.org/gb/en_madeinchina/2005-08/18/content...
Heng was a mathematician, astronomer and geographer. He became chief astrologer and minister under the Emperor An'ti of China. In the year 123 he corrected the calendar to bring it into line with the seasons. In 132 Heng invented the first seismoscope www.sinopro.com/zhang.htm
Zhang Heng was a Chinese mathematician. astronomer and geographer living in one to two centuries in eastern Han Dynasty . At that time the capital Luoyang in the present day Henan province was often haunted by earthquakes. The King levied more taxes to china-corner.com/article_list.asp?id=982
Zhang Heng (78-139), a native of Nanyang in central China's Henan Province, was a mathematician, astronomer and geographer of the Eastern Han Dynasty (25-220). Zhang Heng was the first person in China to construct a rotating celestial globe and also the www1.chinaculture.org/library/2008-02/01/content_26299.htm
