there were the cobblestones : catheads , trollheads , loaves , short and long setts , rounders , morpork sixes , and the eighty-seven types of paving brick , and the fourteen types of stone slab , and the twelve types of stone never intended for street slabs which had got used anyway , and had their own patterns of wear , and the rubbles and the gravels , and the repairs , and the thirteen different types of cellar cover and twenty types of drain lid- he bounced a little , like a man testing the hardness of something .