He started building the Hall of Mirrors which was about expanding Versailles so that it could house all the nobles from his court. He did this because he believed that they would be under his watchful eye and would not be able to plot against the throne. This was an example of absolute power because nobody would be allowed to say no and nobody would be allowed to do anything not approved by the king.
It was to try to find a more accurate way to try to fix holes in pottery its a different ceramic technique.