Therein groweth a stone softer than Alablaster, but being burnt maketh a Plaister harder than that of Paris; wherewith they flower their upper rooms; for betwixt the joyists they lay only long bulrushes, and thereon spread this Plaister, which being throughly dire becomes most solide and hard, so that it seemeth rather to be firmestone than mortar, and is troad upon without all danger.”

John Speed