The Laws of Buoyancy were rules that applied the the rocks growing in the Stone Gardens. The Third Law of Buoyancy was briefly mentioned in The Curse of the Gloamglozer. Earth-scholars in early Sanctaphrax believed that placing a chest of Stormphrax at the floating city's core was breaking the the Third Law of Buoyancy, and that they could find a way to reduce the rock's buoyancy by studying its properties, whereas Sky-Scholars claimed it was necessary for the city's survival.