Middle Ages Technologies
by Dara Rivers

The water clock created by Su Song in 1088 was one of the most important and desired inventions of its time.

It took Su Song approximately 12 years to build an amazingly detailed water clock. Those 12 years that Su Song was building his water clock he also took the time to draw out plans to build his magnificent clock. His clock was a very complicated thing. It included 117 manikins that came out of the tower every hour on the hour and banged gongs and rang bells or carried a tablet that said the hour. It was powered by an 11 foot water wheel with 36 buckets of water mounted on its perimeter. The clock's water wheel only turned 100 times a day and was able to keep time relatively accurately. Su Song’s clock not only kept time but allowed people to observe constellations that were important to Chinese astrology.

Su Song built his astronomical water clock in 1088 C.E., and for 79 years the amazingly complicated clock stood in the capital. One day the Jin army came and disassembled the clock and brought the pieces to their capital which is modern day Beijing . They weren’t able to rebuild it because of the complexity of the clock. They might have been able to manage if they had taken the plans with them, but of course they didn’t. The fact that it was stolen suggests that it was a very important invention and since it was unable to be rebuilt it must have been extremely complicated.


To further prove this point, a couple of years later, a new emperor demanded that Su Song's son Su Xie rebuild the grand clock. After several years of attempting to rebuild the water clock they had quite plainly failed. Since they weren’t able to replicate the clock they decided that Su Song had left out key parts in the building plans, so no one could have a clock such as his.

All this suggests the greed people can have for knowledge. The complexity of Su Song's project in the first place indicates some of that desire. If he really did leave out parts of the building plans, it further shows that he wanted to be alone in his accomplishment. Then, even though no one from the Jin army could rebuild the clock they took it anyway, illustrating the power the desire for knowledge had over them. But greed comes from having something amazing that’s more advanced than what everyone else in the world has.

People today have tried to rebuild the water clock but the best replica we currently have is about five feet tall and doesn’t actually keep time


So even with today’s technology Su Song’s astronomical water clock is unattainable. Whatever implications its story suggests about human nature, Su Song’s three story astronomical water clock is an amazing invention for his time and ours.