Although the Bencao Tujing was an important pharmaceutical work of the age, Su Song is perhaps better known for his work in horology.
The same mechanism would be used by Su Song (1020-1101) in 1088 to power his astronomical clock tower, as well as a chain drive.
Furthermore, Su Song must have taken advantage of the astronomical findings of his political rival and contemporary astronomer Shen Kuo.
A small-scale wooden model was first crafted by Su Song, testing its intricate parts before applying it to an actual full-scale clock tower.
Yet the mechanical legacy of Su Song did not end with his work.
In his memorial, Su Song wrote about this concept:
However, Su Song stated in his writing that after Zhang's death, no one was able to replicate his device, much like his own.
Su Song directly named Zhang's water-powered armillary sphere as the inspiration for his 11th-century clock tower.
The design is based on one by Su Song who built a clock as part of an observatory tower in the period 1088-1092.
Another noteworthy clock, the elaborate Cosmic Engine, was built by Su Song, in 1088.