The first clocks using mechanical movements kept time by regulating a flow of water. For seven hundred years or so, everyone knew that these clocks were invented in Europe in the 13th and 14th centuries. No one is quite sure where exactly, as several cities at roughly the same time erected central clock towers. However, in the middle of the 20th century, Joseph Needham came across a diary written by Su Song that documented a clock that he built in China at the end of the 11th century. The diary had been lost for hundreds of years, and even in China it was well known that mechanical clocks were a European invention.
Needham continued to dig, and eventually found records of four different clocks that had been built in China about the same time. Each only worked for a short period of time. All early clocks required a huge amount of maintenance, and it appears as though the makers of these clocks all either died or moved on after they were built. No one else had the knowledge required to keep them running.
So can we say that mechanical clocks are a Chinese innovation?
In one sense, who cares? But in another sense, this illustrates an important point.
Innovation isn’t just about having ideas. It’s not even simply about executing ideas. To innovate, you have to do both of these things. But you also have to get the idea to spread.
Su wrote a book describing the workings of his clock, but the plans were insufficient to build or maintain a working clock. His son believed that he left out crucial details so that his ideas wouldn’t be stolen.
Su had a very successful career and was widely acclaimed in his time, so from a personal standpoint, this may have been a good strategy. On the other hand, he didn’t get full credit for his ideas for 900 years, mainly because he tried to keep them from spreading.
Finding the right balance between rewarding inventors for successfully executing ideas and getting these ideas to diffuse to improve overall economic outcomes is a difficult problem – one that still bedevils discussion of intellectual property today.
To me though, if your ideas don’t spread, then you aren’t innovating.