78 – Born in Shiqiao of Nanyang, Henan Province, China. Zhang Heng, also known as Pingzi, a Chinese astronomer, geographer, and mathematician.
90 – He was an accomplished writer at twelve.
94 – At sixteen, he left home to pursue his study in the capital cities. He published several well recognized literary writings.
108 – He began his study in Astronomy.
111 – He became a court official and was assigned as the court historian afterwards.
115 – At the age of 37, at the imperial court, he was responsible for observing astronomical phenomena, managing national documents and editing national history.
123 – Corrected the calendar to bring it into line with the seasons.
132 – Heng invented the first seismoscope for measuring earthquakes. The world’s first armilary sphere made of bronze and the first machine that was able to detect the direction of earthquakes.
– He invented the first seismometer, called Houfeng Didong Yi, instrument for measuring the seasonal winds and the movements of the Earth, for measuring earthquakes. He was the first person in China to construct a rotating celestial globe. He also invented the odometer.
139 – He passed away, but some are named after him like the lunar crater, asteroid and mineral to commemorate all his great works.